Playoff Probabilities: Week 15

Another crazy weekend in the NFL last week, as wins by both the Broncos and Giants resulted in huge swings in the playoff probabilities. As always, these numbers come courtesy of Chris Cox at NFL-forecast.com and are generated with the help of his NFL-Forecast software app, which uses the win probabilities generated by the team efficiency model to simulate the NFL season 5,000 times. And if you don't buy the game probabilities from Advanced NFL Stats, you can tweak them as much as you like to generate your own playoff projections. I encourage everyone to download the app and test out your own scenarios.

While the Cowboys' overall probability dropped by 30 points following their loss to the Giants, chances are that their ultimate playoff fate won't be decided until the teams meet again in Week 17. For the Giants to clinch the division before then, they'd have to win both of their games and Dallas would have to lose to Philadelphia (14% probability). For Dallas to clinch before then, they'd have to win their next two games while the Giants lose both of theirs (5% probability). In total, there is a four in five chance that the NFC East will be decided the final week of the season. Mark your calendars.

Elsewhere in the NFC, Green Bay has the #1 seed all but locked up, and the eventual winner of the East will almost surely get the #4 seed, leaving San Francisco and New Orleans to fight over which team gets the #2 seed and the accompanying first-round bye.

The outcome of that race is no small deal. Especially for a weaker team like the 49ers, the fewer games you play means the greater chance that randomness will let you sneak past a stronger opponent. If they enter the playoffs as the #2 seed, for example, the 49ers would have a 34% probability of making it to the NFC Championship game. That isn't very high, considering all they would need to do is win one game at home, but as the #3 seed, this probability drops to just 9%. Which brings us to this week's high leverage games:

High Leverage Games of the Week

Pittsburgh at San Francisco | Monday, December 19 | 8:30 pm ET

Playoff Prob. SF WinPIT Win
PIT >99100
SF 100100

The leverage of this game has nothing to do with the teams' overall playoff probabilities (clearly) and everything to do with their seeding. Pittsburgh is still neck-and-neck with Baltimore for the AFC North and both are projected to finish the season strong. Though Baltimore is expected to perform slightly worse than the Steelers, the Ravens own the tiebreaker, meaning the Steelers will have to win the division outright. If they lose this game, their chances of doing so drop to 23%.

As discussed, securing a first-round bye is especially important for the 49ers, but their loss last week to the Cardinals dropped their chances of doing so a whopping 40 percentage points to 28%. An upset win here would raise that number back up to 52%.

Detroit at Oakland | Sunday, December 18 | 4:05 pm ET

Playoff Prob. OAK WinDET Win
DET 6191
OAK 4722

Oakland needs to win to keep pace with the unstoppable force that is Tim Tebow. Already a game behind the Broncos, a loss to Detroit would put Oakland in a fairly large hole. Even if the Raiders followed up by winning both of their final two games, they would still have just a 25% probability of winning the West. For Detroit, on the other hand, a loss would give the rest of the NFC an opportunity to gain ground in the wild card race, boosting the probabilities of the Bears, Cardinals, and Seahawks to 25, 10, and 6%, respectively.

New York Jets at Philadelphia | Sunday, December 18 | 4:15 pm ET

Playoff Prob. PHI WinNYJ Win
NYJ 2866
PHI 40

The Jets have been right on the cusp all season, with a playoff probability that has neither risen higher than 50% nor fallen lower than 20. Baltimore and Pittsburgh have the #5-seed wild card spot more or less locked up, and the Jets' chances of overtaking the Patriots are minuscule (having lost to NE twice), so their hopes rest on keeping hold of the final wild card spot in the AFC.

The competition: Cincinnati, Tennessee, and the 2nd place team in the AFC West. While no one of these teams presents a formidable challenge, as a whole, there is a 60% chance that one of the three will emerge to knock the Jets out of position. The model sees the game against the Eagles as the most difficult game remaining on the Jets' schedule, so if they win here, their probability of fending off said competition increases to 66%.

For the Eagles (and their fans), the nightmare of the 2011 season is almost over, and a loss here would make it official (there will be no 7-9 playoff teams this year). If the Eagles run the table, however, there's a 14% probability that they could make the postseason at 8-8.

News & Notes

  • With back-to-back wins against the 49ers and Cowboys, could Arizona be making a run at the playoffs after starting the season 1-6? Their remaining schedule is Cleveland, Cincinnati, and Seattle—beat all three, and there's a 42% probability the Cardinals grab a wild card spot.
  • Undefeated season watch: Probability of the Packers going undefeated is up to 47%, including a 10% probability to close out with a Super Bowl win.

The probabilities below are the result of simulating the season 50,000 times using the game-win probabilities from the team efficiency model. They may not add up to 100 (in percent form) due to rounding. Enjoy.

AFC EAST
TeamRecWins1st2nd3rd4th
NE10-312.2>99000
NYJ8-59.30>9900
BUF5-86.6007525
MIA4-95.1002575
AFC NORTH
TeamRecWins1st2nd3rd4th
PIT10-312.4524800
BAL10-311.9485200
CIN7-68.8001000
CLE4-94.7000100
AFC SOUTH
TeamRecWins1st2nd3rd4th
HOU10-312.6100000
TEN7-68.509820
JAC4-95.202980
IND0-130.8000100
AFC WEST
TeamRecWins1st2nd3rd4th
DEN8-59.4792010
OAK7-68.71956214
SD6-77.21226017
KC5-85.9121879
NFC EAST
TeamRecWins1st2nd3rd4th
NYG7-68.9633070
DAL7-68.73450160
PHI5-86.8320717
WAS4-95.201693
NFC NORTH
TeamRecWins1st2nd3rd4th
GB13-015.3100000
DET8-59.4085150
CHI7-68.5015850
MIN2-113.0000100
NFC SOUTH
TeamRecWins1st2nd3rd4th
NO10-312.296400
ATL8-59.949600
CAR4-95.0006832
TB4-94.8003268
NFC WEST
TeamRecWins1st2nd3rd4th
SF10-311.4100000
ARI6-77.7056440
SEA6-77.1044560
STL2-112.9000100


AFC Percent Probability Playoff Seeding
Team1st2nd3rd4th5th6thTotal
HOU314028000100
NE272644400>99
PIT1521160480>99
DEN004750483
BAL271380511>99
NYJ000004142
OAK0001901434
CIN000002020
TEN000001818
SD0001023
KC0001001
MIA0000000
BUF0000000
JAC0000000
CLE0000000
IND0000000

NFC Percent Probability Playoff Seeding
Team1st2nd3rd4th5th6thTotal
GB>9900000100
NO06135040100
SF03859200100
NYG000630164
ATL0030671788
DET0000205676
DAL002321338
CHI000071421
ARI0000167
SEA0000134
PHI0003003
STL0000000
TB0000000
WAS0000000
MIN0000000
CAR0000000


AFC Percent Probability to Advance
TeamDivision RoundConference GameSuper BowlSup Bowl Champion
HOU95643923
PIT85502716
NE8742199
BAL7834146
DEN24410
NYJ11310
OAK11200
CIN5100
TEN4100
SD1000
KC0000
BUF0000
MIA0000
CLE0000
IND0000
JAC0000


NFC Percent Probability to Advance
TeamDivision RoundConference GameSuper BowlSup Bowl Champion
GB100725226
NO86552310
NYG421673
SF712772
DET341041
ATL32931
DAL24831
CHI7210
PHI2100
ARI2000
SEA1000
WAS0000
MIN0000
CAR0000
TB0000
STL0000


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11 Responses to “Playoff Probabilities: Week 15”

  1. Anonymous says:

    Genuinely curious how it is possible that the Saints have a better chance of winning the SB should they get there than the Packers winning should they get there.

  2. Brian Burke says:

    Don't know for sure, but I'd speculate they might get an easier matchup in the div round.

  3. Anonymous says:

    Shouldn't that show up in the 'Make Super Bowl' column though?
    As far as conditional probability goes:
    GB wins 22/43 SB's
    NO wins 22/39 SB's.
    It would seem to be a necessary implication that either NO is stronger by your model (its not) or that that somehow NFC and AFC matchups arent independent variables. While not completely independent(perhaps there are some factors that make NO's potential matchups better in the case it makes the SB), this does not explain the discrepancy.

    Unless there's something very basic I'm missing here, the divisional round being an easier matchup shouldn't matter in this case?

  4. Josh Katz says:

    That is odd... I'll look into it. Perhaps there is a glitch in the matrix.

  5. Anonymous says:

    perhaps the simulations use the same random number to simulate all the games in each week so there is a correlation between weaker teams winning the NFC and AFC? or there is serial correlation in the random number generator giving a similar effect?

    also 5000 isn't that big of a sample size. For a team like GB that made 2000 SBs in the simulation the stdev on the winning percentage is ~ .01 so if two teams have a SB winning percentage of .55 and .57 there is a reasonable chance the simulations are going to have the .55 team with a higher SB win rate.

  6. Anonymous says:

    Hehehe This is the same Anon as before. I just took my final for Statistics today, and for a sample that large, means that far off are 2*(5000)^.5 stds away. Meaning, that is certainly not the answer.

  7. Josh Katz says:

    Chris can speak to the random number gen better than I could, but the numbers in the table are actually drawn up using significantly more than 5000 sims--I'm fairly certain it's not a sample size issue.

  8. Chris says:

    I had the wrong team efficiency rating entered for New Orleans. Both my on-line software and my blog are now updated with the correct rating for the Saints. Sorry for the confusion, especially to Josh. I really appreciate the time he takes to do these write ups.

  9. Josh Katz says:

    No worries, tables now updated with the correct values. And thanks to anonymous commenter #1 for catching that--though I'm sure the people of New Orleans will be quite displeased to see their team's probability of a Super Bowl win drop by more than half.

  10. James says:

    To nit-pick some more, can we see the playoff success odds with an adjusted Houston? They are really messing up all the numbers.

  11. Josh Katz says:

    James--Getting the playoff success probabilities for an adjusted Houston would actually be a little tricky... In terms of seedings, putting their adjusted numbers in gives them a 50% probability of entering the playoffs as the #3 seed, and gives the biggest seeding boost to Pittsburgh, upping their probability of securing the #1 seed to 30%. (PIT has lost to the Texans, so they have the most to gain.)

    But I wouldn't underestimate the Texans, even without Schaub under center. Their defense and running game are still very solid, and, as demonstrated last Sunday, Yates JUST WINS.

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