Thursday, January 29, 2009

NFL Wrapup: APR Pick Reliability

2008 Navigation Links

Read this for a description of APR

Over the course of the regular season, APR picked 240 NFL games week 2 to week 17. I am counting the Bengals @ Eagles tie game as a push in the following tallies.

Visitor vs Home:

Visitor
Won
Home
Won
Total
Picked Right6990159
Picked Wrong344680
Total103136239

APR picked the home team to win 124 times (90 right + 34 wrong). Since 136 home teams won, that's pretty good evidence that some kind of factor should be added to favor home teams in generating picks.

Picks by Matchup Ratio

The matchup ratio (ρ) for each game is the quotient of the corresponding power indexes for each team (larger divided by the smaller). It is intended to be an indication of "pick confidence": ρ values near 1.0 involve teams judged to be very close in power, while large values indicate more of a mismatch.

Range Picked
Right
#
Games
%PV+HWPV+VW
ρ<1.015955.6%23
1.01<=ρ<1.05264163.4%98
1.05<=ρ<1.10294663.0%1115
1.10<=ρ<1.15214151.2%910
1.15<=ρ<1.20243275.0%510
1.20<=ρ<1.30212875.0%58
1.30<=ρ<1.50242982.8%311
1.50<=ρ 91369.2%24

  • "PV+HW" stands for "Picked Visitor and Home Won", and indicates the number of games in each range where APR incorrectly picked the visitor to win (and could be picked up by giving home teams more power).

  • "PV+VW" stands for "Picked Visitor and Visitor Won", and indicates the number of games in each range where APR correctly picked the visitor to win (and could be lost by giving home teams more power).

  • This indicates that simply giving home teams more power would cost more correctly picked games (where the visiting team wins) than it would gain.

  • The drop off of accuracy for ρ >= 1.50 is due to the fact that very large values of ρ are only seen at the very beginning of the season, when APR only has a few games to produce power indexes.

NFL Wrapup: APR Strength of Schedule

2008 Navigation Links

Read this for a description of APR.

How This Was Computed

  1. The unweighted version of APR (i.e., all games have the same weight) is computed for all regular season games.

  2. The 16-game schedules are collated for each team.

  3. For each schedule, every team on the schedule is mapped to its power index computed in step 1. This yields a list of 16 power index values for each team (divisional opponents are counted twice; no adjustment is made for home vs away games).

  4. The list of power index values is then averaged, yeilding a "Strength of Schedule" power index for each team.

As usual, a higher power index value indicates a more difficult schedule.

The Schedule Power Table

Ordered from weakest schedule (top) to strongest schedule (bottom).

Schedule
Power
TeamPlayoffs?
1.239Buffalo Bills
1.244San Francisco 49ers
1.249New York Jets
1.251Miami DolphinsAFC #3
1.252New England Patriots
1.262Arizona CardinalsNFC #4
1.267Seattle Seahawks
1.268Denver Broncos
1.278Atlanta FalconsNFC #5
1.281San Diego ChargersAFC #4
1.283New Orleans Saints
1.283Tampa Bay Buccaneers
1.283Tennessee TitansAFC #1
1.284St. Louis Rams
1.290Carolina PanthersNFC #2
1.293Washington Redskins
1.293Chicago Bears
1.294New York GiantsAFC #1
1.295Philadelphia EaglesNFC #6
1.296Green Bay Packers
1.297Oakland Raiders
1.299Kansas City Chiefs
1.302Dallas Cowboys
1.303Minnesota VikingsNFC #3
1.311Baltimore RavensAFC #6
1.314Indianapolis ColtsAFC #5
1.315Houston Texans
1.321Jacksonville Jaguars
1.328Detroit Lions
1.328Pittsburgh SteelersAFC #2
1.344Cincinnati Bengals
1.346Cleveland Browns

Comments:

  • The range of values is actually pretty compact; relatively small differences in schedules can make a big difference in where a team ends up (c.f. the Titans compared to the rest of the AFC South).

  • Every AFC East team is in the weakest 8, and all are weaker the Arizona Cardinals and the San Diego Chargers.

  • Every NFC West team except the St. Louis Rams is also in the weakest 8.

  • Every AFC North team is in the strongest 8.

  • Every AFC South team except the Tennessee Titans is also in the stronget 8.

  • There's no obvious correlation between schedule power and playoff appearance—the playoff teams seem to be scattered pretty evenly; and both the #1 seeds and the NFC #2 seed are pretty near the middle of the pack.

  • The Browns and Bengals placement make it hard for the Lions to argue that they went winless because of injuries, a tough schedule, and a bad team (though to be fair, the Browns got their four wins before Derek Anderson and Brady Quinn were both on IR).

Monday, January 26, 2009

NFL Wrapup: APR Picks by Team

2008 Navigation Links

Read this for a description of APR.

APR's pick standings by team for the 2008 season. Because there are no power indexes until after the first week of play, only 15 weeks of play were picked.

RecordTeam(s)Comments
15-0-0 Lions Unsurprisingly, APR works best on bad teams that lose a lot, and good teams that win a lot.
14-1-0 Seahawks ibid
12-2-1 Eagles 12 correctly-picked games is a strong argument that the Eagles deserved their high rank after all (so is making it to the NFC Championship game).
12-3-0 Chiefs, Patriots, Cardinals, Rams Excellent results, considering the Patriots went from #24 (week 6) to #6 (week 17), and the Cardinals went from #5 (week 5) to #24 (week 16).
11-4 Cowboys, Chargers, 49ers, Titans The Chargers are another team that seemed to be over-rated based on their record, but 11 correct picks speaks otherwise.
10-4-1 Bengals They are who APR thought they were.
10-5-0 Ravens, Bears, Jaguars, Steelers 16 teams were picked 10-5 (66.7%) or better, which is pretty good...
9-6-0 Vikings, Browns, Texans, Panthers, Raiders, Saints, Bills, Giants, Colts, Dolphins ...but that means 16 teams were picked 9-6 (60%) or worse, which is not so good.
8-7-0 Packers, Jets, Falcons, Redskins The Packers (#5 to #18), Jets (#4 to #19), and Redskins (#1 to #22) all had late season collapses, and APR did not adjust quickly enough.
7-8-0 Buccaneers The Bucs did not travel well. Through week 15, they were 6-0 at home, but just 3-5 on the road. And then, for good measure, they dropped their last two home games.
6-9-0 Broncos The Broncos win APR's "Upset King of 2008" award. They were 5-4 against teams 8-8 or better, but just 3-4 against teams with losing records, including an inexcusable loss to the 2-14 Chiefs. How do you pick a team like that?

Comments:

  • APR uses a simple exponential decay rate to discount older games. I suspect that this gives early games too much weight and late games too little. A more S-shaped curve will probably yield better results.

  • Under the current configuration, APR's worst per-team record is for the 1987 Seahawks and 1994 Bills (both 2-13).

Friday, January 23, 2009

NFL: Super Bowl Picks

2008 Navigation Links

Read this for a description of APR.
Read this for a description of SRS.

Picks for the Super Bowl

Based on the Championship rankings. Line value is taken from yahoo.com, and is for comparison purposes only.

GameAPRSRSLine
Pittsburgh Steelers @
Arizona Cardinals
Steelers
ρ=1.1191
Steelers
δ=9.48
Steelers
-7

Comments:

  • FWDP ranks the AFC North well above the NFC West, also indicating a Steelers victory. FWDP was a lot more interesting last year when it indicated a win for the (otherwise big underdog) Giants.

  • The Steelers and Cardinals played last year in week 4. That game resulted in the Steelers' first loss of the season.

  • Kurt Warner has 770 yards passing so far in the postseason. 419 of those yards are on passes to Larry Fitzgerald.

  • That's better than 12 times the yards of any other Cardinal receiver except Anquan Boldin (106 yards) and Steve Breaston (77 yards).

  • The Steelers need to take advantage if and when the Cardinals turn the ball over. Turnovers were the difference in the Cardinals' regular season losses to the Redskins, Jets, and Panthers. The immediate corollary is the Steelers need to pressure Kurt Warner all game.

  • The Cardinals have another big weakness: their offense seems to get really conservative when they have much of a lead. In the Divisional-round playoff game against the Panthers, it didn't matter, because Jake Delhomme kept throwing interceptions. But in the Conference Championship Game, the Cardinals let a 18-point lead slip away. Even in the 4th quarter when they were driving for the go-ahead score, they seemed to be content to play for a field goal (which would have given them a very marginal 2-point lead with nearly 3 minutes left for the Eagles to answer).

    With first and goal from the 9, the Cardinals ran on first and second down, gaining just one yard. On 3rd and goal from the 8, the Cardinals settled for what appeared to be another give-up play: a screen pass to running back Tim Hightower. Hightower actually caught the ball outside the 12 yard line. An Eagle defender put a solid hit on Hightower at the 2 yard line, and that should have been the end of the play. But somehow no one wrapped up on Hightower, and he was able to spin away and into the end zone. It was almost an afterthought that the Eagles then also gave up a two-point conversion, which meant a 7-point touchdown would force overtime, instead of clinching a win.

Wednesday, January 21, 2009

NFL: Playoff Seeds of Super Bowl Teams

The playoff seeding system was started in 1975. Since then, every Super Bowl has featured at least one #1- or #2-seeded team.

In the following table, #1 and #2 seeded teams are bolded. Years marked with a '*' are ones with no #1 seeded team. As usual, the year refers to when the regular season started; the actual Super Bowls are played the following calendar year.

YearWinnerLoser
1975Steelers #1Cowboys #4
1976Raiders #1Vikings #1
1977Cowboys #1Broncos #1
1978Steelers #1Cowboys #2
1979Steelers #2Rams #3*
1980Raiders #4Eagles #2*
198149ers #1Bengals #1
1982Redskins #1Dolphins #2
1983Raiders #1Redskins #1
198449ers #1Dolphins #1
1985Bears #1Patriots #5
1986Giants #1Broncos #2
1987Redskins #3Broncos #1
198849ers #2Bengals #1
198949ers #1Broncos #1
1990Giants #2Bills #1
1991Redskins #1Bills #1
1992Cowboys #2Bills #4*
1993Cowboys #1Bills #1
199449ers #1Chargers #2
1995Cowboys #1Steelers #2
1996Packers #1Patriots #2
1997Broncos #4Packers #2*
1998Broncos #1Falcons #2
1999Rams #1Titans #4
2000Ravens #4Giants #1
2001Patriots #2Rams #1
2002Buccaneers #2Raiders #1
2003Patriots #1Panthers #3
2004Patriots #2Eagles #1
2005Steelers #6Seahawks #1
2006Colts #3Bears #1
2007Giants #5Patriots #1
2008Steelers #2 Cardinals #4*

Comments:

  • There's certainly evidence in this list that high playoff seeds aren't as valuable as they used to be:

  • There were 8 #1-vs-#1 matchups 1975 to 1993 (19 seasons).

  • There were 0 #1-vs-#1 matchups 1994 to 2008 (15 seasons).

  • Counting this year, we are on a stretch of 5 Super Bowls not won by a #1 seed. The longest such strech before 2000 was just two years (1979-1980, and 1987-1988).

Monday, January 19, 2009

NFL Championship Round Power Rankings

2008 Navigation Links
Read this for a description of APR

RankTeamW-LPower
Index
This week
1 (↑2)Pittsburgh
Steelers
14-41.5330
(LW × 1.015)
won by 9
vs Ravens
2 (↓1)Baltimore
Ravens
13-61.5317
(LW × 0.975)
lost by 9
at Steelers
3 (↓1)Philadelphia
Eagles
11-7-11.4659
(LW × 0.971)
lost by 7
at Cardinals
4 (-)Indianapolis
Colts
12-51.4346
(LW × 0.998)
Bye
5 (↑1)New England
Patriots
11-51.4307
(LW × 1.005)
Bye
6 (↓1)New York
Giants
12-51.4236
(LW × 0.993)
Bye
7 (-)Tennessee
Titans
13-41.4134
(LW × 0.996)
Bye
8 (-)San Diego
Chargers
9-91.3759
(LW × 1.002)
Bye
9 (↑3)Arizona
Cardinals
12-71.3699
(LW × 1.032)
won by 7
vs Eagles
10 (↓1)Atlanta
Falcons
11-61.3592
(LW × 1.003)
Bye
11 (↓1)Minnesota
Vikings
10-71.3427
(LW × 0.999)
Bye
12 (↓1)Carolina
Panthers
12-51.3336
(LW × 1.003)
Bye
13 (↑1)Miami
Dolphins
11-61.3032
(LW × 0.998)
Bye
14 (↓1)Dallas
Cowboys
9-71.3002
(LW × 0.994)
Bye
15 (-)Houston
Texans
8-81.2956
(LW × 0.996)
Bye
16 (-)New Orleans
Saints
8-81.2864
(LW × 1.000)
Bye
17 (-)Chicago
Bears
9-71.2534
(LW × 0.997)
Bye
18 (↑1)New York
Jets
9-71.2407
(LW × 1.001)
Bye
19 (↓1)Washington
Redskins
8-81.2350
(LW × 0.992)
Bye
20 (↑1)San Francisco
49ers
7-91.2310
(LW × 1.000)
Bye
21 (↓1)Green Bay
Packers
6-101.2287
(LW × 0.998)
Bye
22 (-)Tampa Bay
Buccaneers
9-71.2241
(LW × 1.000)
Bye
23 (-)Cincinnati
Bengals
4-11-11.2072
(LW × 0.994)
Bye
24 (↑1)Buffalo
Bills
7-91.1920
(LW × 1.001)
Bye
25 (↓1)Oakland
Raiders
5-111.1909
(LW × 0.999)
Bye
26 (-)Seattle
Seahawks
4-121.1729
(LW × 1.004)
Bye
27 (-)Jacksonville
Jaguars
5-111.1586
(LW × 0.995)
Bye
28 (-)Denver
Broncos
8-81.1510
(LW × 1.000)
Bye
29 (-)Cleveland
Browns
4-121.1298
(LW × 0.995)
Bye
30 (-)Kansas City
Chiefs
2-141.0764
(LW × 0.999)
Bye
31 (-)St. Louis
Rams
2-141.0580
(LW × 1.003)
Bye
32 (-)Detroit
Lions
0-160.9995
(LW × 0.998)
Bye

Comments:

  • The Steelers regain the top spot (they lost the #1 spot in week 16 after losing to the Titans).

  • The Cardinals climb to the #9 spot (the highest they've been since week 9, just before their close win over the 49ers), and 15 spots higher than they were after their week 16 loss to the Patriots.

  • There can't be much question that the Cardinals were holding back the second half of the season. But... why not? After they lost to the Giants, a bye was pretty well out of reach. One thing they could do is perpetuate the "same old Cardinals" stereotype. I think every single team they played underestimated them. And even now, Mike Tomlin and the Steelers have to be thinking "just how good are these guys, anyway?" Which is just about how the Cardinals want it, I would imagine.

Sunday, January 18, 2009

NFL Championship Game Pick Results

2008 Navigation Links

Read this for a description of APR.
Read this for a description of SRS.
Line picks counted correct when the favored team wins; they do not have to beat the spread to count as a win.

Pick results for the Championship Games.

Eagles (APR, SRS, Line) @ Cardinals
In the first half, the Cardinals just dominated. On offense, they scored at will. On defense, they limited the Eagles to three field goal tries. The second half was a different story. The Cardinals play calling seemed to go conservative on both sides of the ball, while the Eagles started to play with urgency, scoring 3 touchdowns in 3 drives. But once the Eagles regained the lead, it was their turn to be conservative: the Cardinals put together a 14 play touchdown drive that regained the lead, and left the Eagles with just 62 seconds on the game clock to respond, and they could not.

Ravens (APR, SRS) @ Steelers (Line)
The Ravens demonstrated this season that a good defense can cover a multitude of offensive shortcomings, including the inexperience of a rookie quarterback. Holding the Steelers to just 16 points on offense wasn't quite enough; when Joe Flacco started pressing his throws, the interceptions started coming, including a game-sealing pick-6 to Troy Polamalu.

Standings:

This weekOverall
APR:0-24-6
SRS:0-24-6
Line:1-14-6
Unanimous:0-13-5

New power rankings, and the Super Bowl pick to come.

Thursday, January 15, 2009

NFL: Division Rivals in the Conference Championship

As I remarked in the post about winning 3 times in a row, it's moderately unusual for teams from the same division to meet in the playoffs.

It's actually happend a fair number of times in the championship game. In the 40 seasons since 1969, there have been 17 Conference Championship† Games played by teams in the same division:

I'm going to ignore the fact that the 1969 Chiefs @ Raiders was before the AFL-NFL merger, and so it was the final League Championship game for the AFL. The playoffs after the 1970 season featured the first AFC Championship game (not listed).

YearDivisionGameCC Winner in SB
1969AFL WestChiefs @ Raiders(Chiefs won SB)
1971AFC EastColts @ Dolphins(Dolphins lost SB)
1972NFC EastCowboys @ Redskins(Redskins lost SB)
1977AFC WestRaiders @ Broncos(Broncos lost SB)
1978AFC CentralOilers @ Steelers(Steelers won SB)
1979AFC CentralOilers @ Steelers(Steelers won SB)
1980AFC WestRaiders @ Chargers(Raiders won SB)
1980NFC EastCowboys @ Eagles(Eagles lost SB)
1982NFC EastCowboys @ Redskins(Redskins won SB)
1982AFC EastJets @ Dolphins(Dolphins lost SB)
1983AFC WestSeahawks @ Raiders(Raiders won SB)
1985AFC EastPatriots @ Dolphins(Patriots lost SB)
1986NFC EastRedskins @ Giants(Giants won SB)
1989NFC WestRams @ 49ers(49ers won SB)
1992AFC EastBills @ Dolphins(Bills lost SB)
1999AFC CentralTitans @ Jaguars(Titans lost SB)
2008AFC NorthRavens @ Steelers(Steelers won SB)

Comments:

  • The probability of a same-division matchup seems to be much more likely in the AFC (12 examples, counting 1969 AFL) than it is in the NFC (5 examples).

  • The home team is 11-5 in these games, which is not good news for the Ravens.

  • However, the winning team is 9-8 in the Super Bowl, which suggests this situation is no special advantage to the winning team once advancing to the Super Bowl.

Wednesday, January 14, 2009

NFL Championship Game Picks

2008 Navigation Links

Read this for a description of APR.
Read this for a description of SRS.

Picks for the Championship games

Based on the Divisional rankings. Line values are taken from yahoo.com, and are for comparison purposes only.

Picks for week Championship.

GameAPRSRSLine
Philadelphia Eagles @
Arizona Cardinals
Eagles
ρ=1.1375
Eagles
δ=8.85
Eagles
-4
Baltimore Ravens @
Pittsburgh Steelers
Ravens
ρ=1.0405
Ravens
δ=0.13
Steelers
-6

Comments:

  • The Ravens' biggest problem advancing to the Super Bowl is going to be how well they recover from the smash-mouth game they played against the Titans. Even guys that aren't "officially" injured will still be feeling stiff and sore, moreso as the Steelers bang them around. The fact that the Steelers' divisional game was pretty well over early in the 4th quarter means the Steelers will be fresher for this game.

  • I didn't think the Cards could beat the Falcons, and surely not the Panthers, and now I don't think they can beat the Eagles. So they're a cinch to win, right? Well... the Eagles are coming off their own smash-mouth game (though less physical than Ravens/Titans, at least to my eye). Also (as pointed out in the Divisional Round Pick Results), the Eagles played a pretty sloppy game. They will make things a lot harder for themselves if they give the Cardinals' too many extra chances on Sunday.

Tuesday, January 13, 2009

How hard is it to beat a team three times in a row?

Updated to include Ravens @ Steelers outcome.

There's a football cliché that's likely to be repeated a number of times in discussing the upcoming Ravens @ Steelers championship game: "it's hard to beat a team three times in a row".

Here's the breakdown of all playoff games featuring divisional matchups since the 1990-91 season (the first year there were 6 playoff teams from each conference):

Year# Divisional
Matchups
# 2-0
Teams
# 3-0
Teams
1990300
1991211
1992310
1993211
1994321
1995200
1997422
1998310
1999111
2000411
2001100
2002111
2004221
2005100
2006200
2007110
2008211
Total371510

Observations:

  • There were no divisional matchups for 1996 or 2003.

  • The numbers for 2008 are, of course, for games played at this writing complete.

  • Divisional matchups in the playoffs are moderately unusual. Unsurprisingly, the rate seems to have dropped off since the 2002 realignment has reduced the size of divisions to 4 teams each.

  • Divisional matchups featuring one team that swept the other are rare.

  • But once you have a divisional matchup where one team has swept the other, 10 of 15 times (66.7%) the 2-0 team has won.

Games that were the third win in a row:

Winning team in bold.

YearRoundVisitorHome
1991Wildcard Raiders 6 @ Chiefs 10
1993Wildcard Broncos 24 @ Raiders 42
1994Divisional Browns 9 @ Steelers 29
1997Wildcard Dolphins 3 @ Patriots 17
1997Divisional Buccaneers 7@ Packers 21
1999ChampionshipTitans 33 @ Jaguars 14
2000Divisional Eagles 10 @ Giants 20
2002Wildcard Browns 33 @ Steelers 36
2004Wildcard Rams 27 @ Seahawks 20
2008ChampionshipRavens 14@ Steelers 23

Games that were the first loss after two wins:

Winning team in bold.

YearRoundVisitorHome
1992Wildcard Chiefs 0 @ Chargers 17
1994Wildcard Bears 35 @ Vikings 18
1998Wildcard Cardinals 20@ Cowboys 7
2004Wildcard Vikings 31 @ Packers 17
2007DivisionalGiants 21 @ Cowboys 17

Monday, January 12, 2009

NFL Divisional Round Power Rankings

2008 Navigation Links
Read this for a description of APR

RankTeamW-LPower
Index
This week
1 (-)Baltimore
Ravens
13-51.5708
(LW × 1.008)
won by 3
at Titans
2 (↑2)Philadelphia
Eagles
11-6-11.5097
(LW × 1.035)
won by 12
at Giants
3 (↓1)Pittsburgh
Steelers
13-41.5096
(LW × 1.009)
won by 11
vs Chargers
4 (↑1)Indianapolis
Colts
12-51.4379
(LW × 0.994)
Bye
5 (↓2)New York
Giants
12-51.4336
(LW × 0.979)
lost by 12
vs Eagles
6 (↑1)New England
Patriots
11-51.4234
(LW × 1.008)
Bye
7 (↓1)Tennessee
Titans
13-41.4188
(LW × 0.988)
lost by 3
vs Ravens
8 (↑1)San Diego
Chargers
9-91.3728
(LW × 0.983)
lost by 11
at Steelers
9 (↑1)Atlanta
Falcons
11-61.3558
(LW × 0.997)
Bye
10 (↑1)Minnesota
Vikings
10-71.3440
(LW × 1.001)
Bye
11 (↓3)Carolina
Panthers
12-51.3295
(LW × 0.948)
lost by 20
vs Cardinals
12 (↑5)Arizona
Cardinals
11-71.3272
(LW × 1.062)
won by 20
at Panthers
13 (↑2)Dallas
Cowboys
9-71.3082
(LW × 1.006)
Bye
14 (-)Miami
Dolphins
11-61.3055
(LW × 1.002)
Bye
15 (↓3)Houston
Texans
8-81.3004
(LW × 0.995)
Bye
16 (↓3)New Orleans
Saints
8-81.2865
(LW × 0.987)
Bye
17 (↓1)Chicago
Bears
9-71.2566
(LW × 0.995)
Bye
18 (↑3)Washington
Redskins
8-81.2450
(LW × 1.009)
Bye
19 (↑1)New York
Jets
9-71.2388
(LW × 1.003)
Bye
20 (↓2)Green Bay
Packers
6-101.2307
(LW × 0.992)
Bye
21 (↑1)San Francisco
49ers
7-91.2306
(LW × 1.008)
Bye
22 (↓3)Tampa Bay
Buccaneers
9-71.2239
(LW × 0.988)
Bye
23 (-)Cincinnati
Bengals
4-11-11.2147
(LW × 1.002)
Bye
24 (-)Oakland
Raiders
5-111.1922
(LW × 0.991)
Bye
25 (-)Buffalo
Bills
7-91.1903
(LW × 1.001)
Bye
26 (↑2)Seattle
Seahawks
4-121.1685
(LW × 1.014)
Bye
27 (↓1)Jacksonville
Jaguars
5-111.1639
(LW × 0.996)
Bye
28 (↓1)Denver
Broncos
8-81.1507
(LW × 0.990)
Bye
29 (-)Cleveland
Browns
4-121.1358
(LW × 1.001)
Bye
30 (-)Kansas City
Chiefs
2-141.0770
(LW × 0.991)
Bye
31 (-)St. Louis
Rams
2-141.0551
(LW × 1.011)
Bye
32 (-)Detroit
Lions
0-161.0011
(LW × 0.991)
Bye

Comments:

  • The Cardinals are the only remaining team ranked below an eliminated team. But they are now in the top 12, and finally above another (albeit eliminated) playoff team.

  • The Eagles and Steelers are virtually tied. If the Steelers had held on to their 18-point lead, they would have held on to the #2 spot.

  • Since the seeding system was started, Eagles @ Cardinals is just the third championship game without a #1 or #2 seed. Others were in 1987: Vikings (#5) @ Redskins (#3) and 2006: Patriots (#4) @ Colts (#3).

Sunday, January 11, 2009

NFL Divisional Round Pick Results

2008 Navigation Links

Read this for a description of APR.
Read this for a description of SRS.
Line picks counted correct when the favored team wins; they do not have to beat the spread to count as a win.

Pick results for the Divisional Round.

Ravens (APR, SRS) @ Titans (Line)
Certainly the Titans had every chance to win this game, but they looked out of sync for most of the game. Their offense had 3 long drives end on a turover. They had at least two bad/early snaps that could have been (more) disasterous. On the defensive side, the Ravens were held to just 13 points. But Joe Flacco threw some passes that should have been knocked down if not intercepted.

Cardinals @ Panthers (APR, SRS, Line)
In week 10, Jake Delhomme threw 4 interceptions to the Raiders, but the Panthers still managed to pull out the win. This time, they were playing a team that could actually score given that many extra chances at the ball. Though it says something about the Cardinals uncertainty that they kicked so many field goals. A more confident team would have scored at least 40 points in a game like that.

Eagles @ Giants (APR, SRS, Line)
The Eagles' offense didn't exactly light things up (4 punts, 2 interceptions, and a safety). But the Giants couldn't get into the end zone, they couldn't convert on critical 3rd and 4th downs. Add in 2 interceptions and a lost fumble, and it was a very bad day for Big Blue.

Chargers @ Steelers (APR, SRS, Line)
The Chargers might have had a real chance in this game, except for a disasterous 3rd quarter. The Steelers' opening drive took 7:56 off the clock and gave them an 11-point lead. The Chargers next two drives ended on an interception and a muffed punt (and technically, the muffed punt doesn't count as a possession).

Standings:

This weekOverall
APR:2-24-4
SRS:2-24-4
Line:1-33-5
Unanimous:1-23-4

New power rankings, and Championship Game picks to come.

Saturday, January 10, 2009

NFL Playoffs, Overtime, and Winning the Coin Toss

Update 31 Jan 2010: added overtime results for 2010 playoffs.

Since 2001, there have been (at this writing) 98 playoff games played. Of these, 12 (12.2%) have gone to over time. Here is a brief summary, for each game, of the team that won the toss, and the result of their first drive:

SeasonRoundGameWon tossResult
2001Div Raiders @
Patriots
Patriotsscored
2002Div Steelers @
Titans
Titansscored
2003WC Seahawks @
Packers
Seahawkspunt
2003Div Packers @
Eagles
Eaglespunt
2003Div Panthers @
Rams
Panthersmissed FG
2004WC Jets @
Chargers
Jetspunt
2004Div Jets @
Steelers
Jetspunt
2006Div Seahawks @
Bears
Seahawkspunt
2007CCG Giants @
Packers
Packersinterception
2008WC Colts @
Chargers
Chargersscored
2009WCPackers @
Cardinals
Packersfumbled
2009CCGVikings @
Saints
Saintsscored

It should also be observed that of the 4 games listed above that were won on the opening overtime drive, the 2009 Saints were the only team that didn't score last in the regulation period. Which suggests to me that the problem is in the losing teams' defenses, at least as much as which way the coin-toss went the sample space is too small to draw any useful conclusions.

Comments:

  • 2001 Raiders @ Patriots was the "tuck rule" game. The Raiders offense never crossed mid-field after the end of the third quarter. The Patriots scored the final 10 points in regulation, and drove 61 yards in 15 plays for the game-winning field goal.

  • (Since 2001) Most playoff games do not go to overtime.

  • (Since 2001) Most playoff games that do go to overtime are not won on the opening drive.

  • (Since 2001) In the remaining 3 games, there is at least some evidence that poor defense was as much at fault as the mis-called toss for losing the game.

Thursday, January 8, 2009

NCAA: Final Top 30+

2008 Navigation Links

Read this for a description of SRS.
Read this for a description of APR.
Read this for some disclaimers about applying APR to NCAA.

SRS absolutely owned the Bowl game picks (results below). Thus, I present the SRS-based Top 30+:

RankTeamW-LPower
Index
This week
1 (↑1)Florida
AP=1
13-138.7582
(LW + 0.970)
won by 10
at Oklahoma
2 (↓1)Oklahoma
AP=5
12-236.6529
(LW - 1.603)
lost by 10
vs Florida
3 (↑1)USC
AP=3
12-134.1979
(LW + 0.718)
won by 14
vs Penn-St
4 (↓1)Texas
AP=4
12-132.0386
(LW - 1.746)
won by 3
vs Ohio-St
5 (-)Penn-St
AP=8
11-228.3959
(LW - 1.589)
lost by 14
at USC
6 (↑1)TCU
AP=7
11-222.5440
(LW - 0.508)
won by 1
vs Boise-St
7 (↓1)Texas-Tech
AP=12
11-222.2056
(LW - 2.582)
lost by 13
vs Mississippi
8 (-)Missouri
AP=19
10-421.0858
(LW - 1.779)
won by 7
at Northwestern
9 (-)Ohio-St
AP=9
10-320.5819
(LW - 0.103)
lost by 3
at Texas
10 (-)Alabama
AP=6
12-220.0269
(LW - 0.656)
lost by 14
vs Utah
11 (↑2)Utah
AP=2
13-019.6823
(LW + 0.805)
won by 14
at Alabama
12 (-)Boise-St
AP=11
12-119.0201
(LW - 0.345)
lost by 1
at TCU
13 (↑3)Mississippi
AP=14
9-418.8638
(LW + 1.731)
won by 13
at Texas-Tech
14 (↑1)Oregon
AP=10
10-318.6227
(LW + 0.706)
won by 11
vs Oklahoma-St
15 (↓1)Iowa
AP=20
9-418.2946
(LW - 0.049)
won by 21
vs South-Carolina
16 (↓5)Oklahoma-St
AP=16
9-417.7462
(LW - 1.972)
lost by 11
at Oregon
17 (-)California
AP=rv(128)
9-416.6901
(LW - 0.217)
won by 7
vs Miami-FL
18 (-)Arizona
AP=rv(4)
8-515.8185
(LW + 0.261)
won by 10
vs BYU
19 (↑2)Florida-St
AP=21
9-414.6236
(LW + 1.571)
won by 29
vs Wisconsin
20 (↓1)Oregon-St
AP=18
9-414.4389
(LW - 0.223)
won by 3
at Pittsburgh
21 (↓1)Georgia
AP=13
10-313.6219
(LW + 0.493)
won by 12
at Michigan-St
22 (-)Nebraska
AP=rv(64)
9-412.4898
(LW - 0.522)
won by 5
vs Clemson
23 (-)North-Carolina8-511.7904
(LW - 0.580)
lost by 1
vs West-Virginia
24 (↑9)Tulsa
AP=rv(61)
11-311.1922
(LW + 1.935)
won by 32
at Ball-St
25 (↓1)Kansas
AP=rv(2)
8-511.0389
(LW + 0.021)
won by 21
at Minnesota
26 (↑1)Pittsburgh
AP=rv(106)
9-410.3081
(LW - 0.162)
lost by 3
vs Oregon-St
27 (↓2)Clemson7-610.2854
(LW - 0.454)
lost by 5
at Nebraska
28 (↓2)BYU
AP=25
10-39.9352
(LW - 0.580)
lost by 10
at Arizona
29 (-)Rutgers
AP=rv(11)
8-59.5713
(LW - 0.334)
won by 6
vs NC-State
30 (↓2)Boston-Coll
AP=rv(11)
9-59.4115
(LW - 0.515)
lost by 2
at Vanderbilt
31 (↑3)Wake-Forest8-59.1329
(LW + 0.535)
won by 10
at Navy
32 (↑11)LSU
AP=rv(95)
8-58.9902
(LW + 3.144)
won by 35
at Georgia-Tech
33 (↑2)Virginia-Tech
AP=15
10-48.8271
(LW + 0.424)
won by 13
at Cincinnati
34 (↓2)Michigan-St
AP=24
9-48.4315
(LW - 1.164)
lost by 12
vs Georgia
35 (↑2)West-Virginia
AP=23
9-47.8261
(LW + 0.300)
won by 1
at North-Carolina
36 (-)South-Carolina7-67.6455
(LW - 0.375)
lost by 21
at Iowa
37 (↑1)Miami-FL7-67.2325
(LW - 0.003)
lost by 7
at California
38 (↓8)Ball-St
AP=rv(13)
12-26.6882
(LW - 3.158)
lost by 32
vs Tulsa
39 (↓8)Georgia-Tech
AP=22
9-46.5934
(LW - 3.075)
lost by 35
vs LSU
40 (↑6)Connecticut8-56.3192
(LW + 0.836)
won by 18
vs Buffalo

Other teams of note:
43 (↑1)Northwestern
AP=rv(53)
9-45.6839
(LW + 0.027)
lost by 7
vs Missouri
64 (↓8)Rice
AP=rv(8)
9-40.9500
(LW - 2.245)
lost by 24
at W-Michigan

Final BCS AP rankings will be added after they are released. (No post-bowl-games BCS rankings? How very odd.)

Pick Standings

Bowl games were picked in this post.

SRS: 22-12(64.7%)
Line:17-17(50.0%)
APR: 12-22(35.3%)

SRS' record isn't that impressive by regular-season standards. But for some reason, the Line and especially APR just tanked.

Winning Teams Unanimously Picked To Lose

  • Florida Atlantic (Motor City Bowl)
  • Louisiana Tech (Independence Bowl)
  • Western Michigan (Texas Bowl)
  • Vanderbilt (Music City Bowl)
  • LSU (Chick-fil-A Bowl)
  • Mississippi (Cotton Bowl)
  • Tulsa (GMAC Bowl)

Comments:

  • The usual suspects (Florida, Oklahoma, USC, Texas, and Penn State) are still at the top, but there's a lot of differences as you get lower down.

  • APR was only right twice picking against SRS (Oregon in the Holiday Bowl and Utah in the Sugar Bowl).

  • Clearly, APR needs to be adjusted for the NCAA.

  • Lowest ranked teams (according to SRS) to win: Colorado-St (#78), Louisiana-Tech (#89), and Florida-Atlantic (#96).

  • AP ranks Utah #2? Do they really want to give an unbeaten season that much weight?

Wednesday, January 7, 2009

NFL Divisional Game Picks

2008 Navigation Links

Read this for a description of APR.
Read this for a description of SRS.

Picks for the Divisional games

Based on the Wildcard rankings. Line values are taken from yahoo.com, and are for comparison purposes only.

GameAPRSRSLine
Arizona Cardinals @
Carolina Panthers
Panthers
ρ=1.1224
Panthers
δ=6.60
Panthers
-10
Baltimore Ravens @
Tennessee Titans
Ravens
ρ=1.0855
Ravens
δ=1.49
Titans
-3
San Diego Chargers @
Pittsburgh Steelers
Steelers
ρ=1.0712
Steelers
δ=4.56
Steelers
-6
Philadelphia Eagles @
New York Giants
Giants
ρ=1.0042
Giants
δ=0.17
Giants
-4

Comments:

  • Unanimous, except for Ravens @ Titans.

  • On the one hand, the Ravens have played really strong so far this season. On the other hand, there seems to be games where their offense just disappears. They averaged just 10.4 points/game in their five losses.

  • Eagles @ Giants is really close, by both APR's and SRS' measure.

Tuesday, January 6, 2009

NFL Wrapup: The Top 10 Upsets, as Determined by APR

Determining Upset Magnatude

Originally, I was going to measure upset magnatude using the match-up ratio (the "ρ" value) originally published for the game. But after some (unposted) analysis, it seems clear that the match-up ratios are not comparable from week-to-week. They start out very high at the start of the season, and decline as it goes on.

So the first modification I made was to use the APR power index values from the second-to-last week of the season (I avoided the last week to rule out anomolous effects of teams resting their starters). However, the normal APR algorithm gives less weight to early season games.

Rather than try to justify why the week 2 Chargers @ Broncos game was one of the top-10 upsets of the season, I decided to use the unweighted version of APR power indexes, which gives all games played equal weight.

Determining the Top 10 Upsets

Using the unweighted APR power indexes for week 17, a list of all games where the predicted winner lost was compiled. This list was then sorted according to each game's match-up ratio (ρ).

Any loss that was (in my opinion) attributable to teams not playing all-out was eliminated from the list. The top 10 games from this list is presented below.

The Top 10 Upsets of the 2008 Season

As determined by the unweighted APR power indexes from week 16.

  1. Week 5: Buccaneers 13, Broncos 16 (ρ=1.1168)
    From week 3 to week 15, APR had the Buccaneers ranked in the top 10. Maybe they just weren't ready to play at Mile High, but somehow the Buccaneers let the Broncos give them their second loss.
  1. Week 16: Jets 3, Seahawks 13 (ρ=1.1312)
    Because the Jets couldn't put up two touchdowns on the Seahawks, they went from "win and you're in" to "win (and with help) you're in". The win and the help never came.
  1. Week 3: Jaguars 23, Colts 21 (ρ=1.1383)
    The Jaguars won just 5 games this year, and this was one of them. It's hard to argue against Peyton Manning as MVP when a key loss like this is largely attributable to Manning's early season health problems.
  1. Week 7: Jets 13, Raiders 16 (ρ=1.1385)
    Because the Jets couldn't put up two touchdowns on the Raiders... yeah, there seems to be a theme here. You might argue whether Jets @ Seahawks or Jets @ Raiders is the bigger upset, but they're both pretty bad.
  1. Week 11: Broncos 24, Falcons 20 (ρ=1.1398)
    The Falcons had a chance at the #2 seed going into week 17. If they had won this game (their only home loss of the season), they would have had a much better chance.
  1. Week 12: Jets 34, Titans 13 (ρ=1.1398)
    At the time, this didn't seem like that much of an upset. But that was (right) before the Jets went on a 1-4 skid, and finished out of the playoffs.
  1. Week 17: Raiders 31, Buccaneers 24 (ρ=1.2029)
    Coming in to week 17, the Buccaneers still had a chance for the playoffs (and would've been in, had they won). All they had to do was beat the 4-11 Raiders. But there was no defense, no win, and no playoffs.
  1. Week 6: Rams 19, Redskins 17 (ρ=1.2192)
    It says something about how bad the Rams were this year that this game is on this list in spite of the Redskins late-season troubles.
  1. Week 6: Giants 14, Browns 35 (ρ=1.2483)
    Easily the low-point to the Giants season. Given the way the offense was struggling (Eli Manning threw 3 interceptions), the defense would've needed a masterful performance to keep them in the game. Instead, the Browns scored at will for much of the game.
  1. Week 7: Cowboys 14, Rams 34 (ρ=1.3023)
    Brad Johnson will get his fair share of blame for this loss (the Cowboys didn't have a second drive for more than 21 yards until garbage time). But the defense was at fault, too: the Rams scored on their first 3 drives, and didn't punt for the second time until the 3rd quarter.

    If the Cowboys had won this game, they wouldn't have needed a win over the Eagles in week 17 to get in the playoffs.

Eliminated Games

The only game eliminated from the above list is the Titan's week 15 loss to the Texans (which would have been the #5 upset). At that point in the season, the Titans had already clinched the AFC South and a bye week, and only needed to beat the Steelers in week 16 to clinch the #1 seed in the playoffs. This was a meaningless game for the Titans.

Monday, January 5, 2009

NFL Wildcard Power Rankings

2008 Navigation Links
Read this for a description of APR

RankTeamW-LPower
Index
This week
1 (-)Baltimore
Ravens
12-51.5585
(LW × 1.029)
won by 18
at Dolphins
2 (-)Pittsburgh
Steelers
12-41.4962
(LW × 1.007)
Bye
3 (↑1)New York
Giants
12-41.4650
(LW × 1.007)
Bye
4 (↑3)Philadelphia
Eagles
10-6-11.4589
(LW × 1.032)
won by 12
at Vikings
5 (↓2)Indianapolis
Colts
12-51.4462
(LW × 0.988)
lost by 6
at Chargers
6 (↓1)Tennessee
Titans
13-31.4357
(LW × 0.997)
Bye
7 (↓1)New England
Patriots
11-51.4123
(LW × 0.995)
Bye
8 (-)Carolina
Panthers
12-41.4025
(LW × 0.993)
Bye
9 (↑1)San Diego
Chargers
9-81.3967
(LW × 1.004)
won by 6
vs Colts
10 (↓1)Atlanta
Falcons
11-61.3603
(LW × 0.975)
lost by 6
at Cardinals
11 (-)Minnesota
Vikings
10-71.3424
(LW × 0.971)
lost by 12
vs Eagles
12 (↑2)Houston
Texans
8-81.3065
(LW × 0.995)
Bye
13 (-)New Orleans
Saints
8-81.3041
(LW × 0.990)
Bye
14 (↓2)Miami
Dolphins
11-61.3029
(LW × 0.968)
lost by 18
vs Ravens
15 (-)Dallas
Cowboys
9-71.3007
(LW × 1.010)
Bye
16 (-)Chicago
Bears
9-71.2629
(LW × 0.991)
Bye
17 (↑3)Arizona
Cardinals
10-71.2495
(LW × 1.018)
won by 6
vs Falcons
18 (↓1)Green Bay
Packers
6-101.2413
(LW × 0.991)
Bye
19 (↓1)Tampa Bay
Buccaneers
9-71.2394
(LW × 0.991)
Bye
20 (↓1)New York
Jets
9-71.2351
(LW × 0.994)
Bye
21 (↑1)Washington
Redskins
8-81.2333
(LW × 1.011)
Bye
22 (↓1)San Francisco
49ers
7-91.2204
(LW × 0.998)
Bye
23 (↑1)Cincinnati
Bengals
4-11-11.2124
(LW × 1.006)
Bye
24 (↓1)Oakland
Raiders
5-111.2025
(LW × 0.994)
Bye
25 (-)Buffalo
Bills
7-91.1890
(LW × 0.993)
Bye
26 (-)Jacksonville
Jaguars
5-111.1683
(LW × 0.997)
Bye
27 (-)Denver
Broncos
8-81.1620
(LW × 0.993)
Bye
28 (-)Seattle
Seahawks
4-121.1521
(LW × 1.001)
Bye
29 (-)Cleveland
Browns
4-121.1344
(LW × 1.005)
Bye
30 (-)Kansas City
Chiefs
2-141.0865
(LW × 0.994)
Bye
31 (-)St. Louis
Rams
2-141.0438
(LW × 0.996)
Bye
32 (-)Detroit
Lions
0-161.0103
(LW × 0.990)
Bye

Comments:

  • The Ravens solidify their ranking at #1 with a solid win over the Dolphins. They will have a tougher challenge next week at the Titans, though.

  • The Giants benefit from the Eagles' win and the Colts' loss to move up to #3.

  • Peyton Manning now has 6 one-and-done playoff appearances. I don't know if that's a record, but after a quick survey, the only others I saw anywhere close were Joe Montana and Warren Moon, both with 4. (To be fair, most quarterbacks don't have 6 playoff appearances of any kind.)

  • The Cardinals are still way down there. But they did play the Panthers close in week 8 (losing by 4), so it's not impossible that the Cardinals could make it to the Championship game. Which is not a sentence I ever expected to seriously compose, but there you go.

  • You can also get an idea of how indirect power affects rankings, by looking at how, for example, the Bengals and Raiders swapped places.

Sunday, January 4, 2009

NFL Wildcard Games Pick Results

2008 Navigation Links

Read this for a description of APR.
Read this for a description of SRS.
Line picks counted correct when the favored team wins; they do not have to beat the spread to count as a win.

Pick results for Wildcard Weekend.

All picks were unanimous.

I thought I was going to be writing about 4 correctly picked games. Hah!

Falcons @ Cardinals: wrong
The Cardinals' defense played their best game of the year. They came up with 2 interceptions, a fumble recovered for a touchdown, and a safety. The Cardinals' offense had a pretty ordinary day, but with the defense playing lights-out, it was enough.

Colts @ Chargers: wrong
In their last 4 meetings, the Colts are now 1-3 vs the Chargers including two playoff games. Scifres (the punter) is clearly the MVP of the game: the Colts had 10 drives start at or inside their 20 yard line, including 4 at or inside the 10. Sproles running game was big too, but all those long fields Manning faced was key to the Chargers holding the Colts to just 17 points.

Ravens @ Dolphins: right
The Ravens weren't bothered by the Wildcat in week 7, and they weren't bothered by it here, either. Through 2006, only one team has won a playoff game and thrown 4 interceptions.

Eagles @ Vikings: right
In the regular season, the Eagles struggled when they couldn't run the ball, which seems like a problem for them going up against Minnesota's run defense. And if the Vikings had been able to hold them to a handful of field goals, it would have been. But Tarvaris Jackson threw a pick-6, and Brian Wesbrook got free for a long touchdown reception, and the Vikings just couldn't catch up.

Standings:

This weekOverall
APR:2-22-2
SRS:2-22-2
Line:2-22-2
Unanimous:2-22-2

New power rankings, and Divisional Round picks to come.