How did the Patriots clinch the AFC East?
2015-12-17
Late Monday night, as the Dolphins fell to the Giants, the NFL announced that the Patriots had just clinched the AFC East. A team won its division by having the weakest team in its division lose. That’s bizarrely full of schadenfreude.
A team clinches its division when its worst possible outcome is still better than the best possible outcome of its rivals - in this case, comparing the Patriots and the Jets. Currently, with three weeks remaining, the Patriots have 11 wins, and the Jets 8. If we assume that the Patriots lose their final three regular season games, and the Jets win theirs, they’d be tied at 11 wins at the end of the season, so the NFL’s tie-breaking procedures go into effect.
The first tie-breaker is the head-to-head record. Back in Week 7, the Patriots beat the Jets; and we’re hypothesizing that the Jets beat the Patriots in Week 16. Neither team has an advantage.
The second tie-breaker is the record of games played within the division. Since we know they split games against each other 1-1, we only have to also look at games against the Bills and Dolphins. The Patriots have already swept the Bills, and beat the Dolphins once. Falling to the Dolphins in Week 17 would put them at 4-2. The Jets have beat the Dolphins twice, and lost to the Bills once. Beating the Bills in Week 17 would put them at 4-2 as well, so we have to move to the next tie-breaker.
The third tie-breaker is the record in common games (note that this and the next tie-breakers are in a different order for divisional and conference opponents, because of the 14 non-head-to-head games, 12 of them are common, making this a more relevant tiebreaker). We’ve already covered the AFC East foes (3-1 each), so we look at records against the AFC South and NFC East. The Patriots went 3-1 against the NFC East (losing only to the Eagles), and already have 3 wins against the AFC South (with a projected loss to the Titans in Week 15), for a 9-3 record. The Jets also are 3-1 against the AFC South (losing to the Texans), and a Week 15 win against the Cowboys would also put them at 3-1 against the NFC East (also falling to the Eagles). Those two 9-3 records match them up, so onward we go.
The fourth tie-breaker becomes the AFC record. That’s comprised of the AFC East record (4-2 each), the AFC South record (3-1 each), and then their records against their substitution foes (since a team plays its own division twice, but can’t play itself, it uses two teams as a substitute for itself - the two teams who finished in the same place in their division, drawn from the two divisions in the AFC that you aren’t playing). The Patriots drew the Steelers (win) and the Broncos (loss); the Jets drew the Browns (win) and the Raiders (loss). That 1-1 record makes for a total 8-4 record, necessitating yet another tiebreaker.
At this point it’s worth pausing - both teams would project to five losses, evenly distributed in the five interesting groupings: head-to-head, in-division, AFC South, NFC East, and substitution team. Without that distribution, the tie would be broken by now. The next two tie-breakers are *strength* tie-breakers, which calculates the win-loss percentage of a group of opponents. Since each comparison is within a group of teams of the same size, we can, for simplicity, only count wins (since win-loss percentage is “wins divided by total games”, and “total games” is “16 times teams compared”, we can drop both denominators for simplicity). For further simplicity, if we’re comparing two groups of teams that overlap, we can drop out overlapped teams, since they’d add the same amount to both teams.
The fifth tie-breaker is strength of victory, determining how good were the opponents that each team beat. We count duplicate wins twice. Both teams beat (or project to beat) the Bills, Dolphins, Colts, Jaguars, Redskins, Giants, Cowboys, and each other (at 11 projected wins each, we can discard both); the Patriots also beat the Bills (a second times), Texans, and Steelers; the Jets also beat the Dolphins (a second time), Titans, and Browns. Assuming that the Patriots extra opponents lose out, and the Jets opponents all win out, we can calculate their relative strength of victory (none of the extra opponents on each side play each other, although the Titans play both the Texans and Patriots, Miami plays the Patriots, and Buffalos takes on the Jets). The Bills (6 wins), Texans (6) and Steelers (8) give the Patriots 20 net strength of victory points; the Dolphins (5+3), Titans (3+3) and Browns (3+3) also give the Jets 20 net strength of victory points. If the Dolphins had won, the Jets could still achieve 21 net strength of victory, so the Patriots wouldn’t be able to clinch yet. Instead, we move deeper into the tiebreakers.
The sixth tie breaker is then strength of schedule. Twelve of the games are against common opponents, so will have an identical strength, and two more games are head-to-head (so have the identical strength, or we wouldn’t be in tie-breakers). We only have to compare the substitution teams. The Patriots have the Steelers (8), and the Broncos (11+1, because they will have to have beaten the Steelers in Week 15 in this scenario) for 20 net schedule strength points. The Jets have the Browns (3+3) and the Raiders (6+3), for a maximum of 15 net schedule strength points.
The NFL finally got to use half of its tie breaking steps. Maybe someday we’ll see the coin toss at step 12.
A team clinches its division when its worst possible outcome is still better than the best possible outcome of its rivals - in this case, comparing the Patriots and the Jets. Currently, with three weeks remaining, the Patriots have 11 wins, and the Jets 8. If we assume that the Patriots lose their final three regular season games, and the Jets win theirs, they’d be tied at 11 wins at the end of the season, so the NFL’s tie-breaking procedures go into effect.
The first tie-breaker is the head-to-head record. Back in Week 7, the Patriots beat the Jets; and we’re hypothesizing that the Jets beat the Patriots in Week 16. Neither team has an advantage.
The second tie-breaker is the record of games played within the division. Since we know they split games against each other 1-1, we only have to also look at games against the Bills and Dolphins. The Patriots have already swept the Bills, and beat the Dolphins once. Falling to the Dolphins in Week 17 would put them at 4-2. The Jets have beat the Dolphins twice, and lost to the Bills once. Beating the Bills in Week 17 would put them at 4-2 as well, so we have to move to the next tie-breaker.
The third tie-breaker is the record in common games (note that this and the next tie-breakers are in a different order for divisional and conference opponents, because of the 14 non-head-to-head games, 12 of them are common, making this a more relevant tiebreaker). We’ve already covered the AFC East foes (3-1 each), so we look at records against the AFC South and NFC East. The Patriots went 3-1 against the NFC East (losing only to the Eagles), and already have 3 wins against the AFC South (with a projected loss to the Titans in Week 15), for a 9-3 record. The Jets also are 3-1 against the AFC South (losing to the Texans), and a Week 15 win against the Cowboys would also put them at 3-1 against the NFC East (also falling to the Eagles). Those two 9-3 records match them up, so onward we go.
The fourth tie-breaker becomes the AFC record. That’s comprised of the AFC East record (4-2 each), the AFC South record (3-1 each), and then their records against their substitution foes (since a team plays its own division twice, but can’t play itself, it uses two teams as a substitute for itself - the two teams who finished in the same place in their division, drawn from the two divisions in the AFC that you aren’t playing). The Patriots drew the Steelers (win) and the Broncos (loss); the Jets drew the Browns (win) and the Raiders (loss). That 1-1 record makes for a total 8-4 record, necessitating yet another tiebreaker.
At this point it’s worth pausing - both teams would project to five losses, evenly distributed in the five interesting groupings: head-to-head, in-division, AFC South, NFC East, and substitution team. Without that distribution, the tie would be broken by now. The next two tie-breakers are *strength* tie-breakers, which calculates the win-loss percentage of a group of opponents. Since each comparison is within a group of teams of the same size, we can, for simplicity, only count wins (since win-loss percentage is “wins divided by total games”, and “total games” is “16 times teams compared”, we can drop both denominators for simplicity). For further simplicity, if we’re comparing two groups of teams that overlap, we can drop out overlapped teams, since they’d add the same amount to both teams.
The fifth tie-breaker is strength of victory, determining how good were the opponents that each team beat. We count duplicate wins twice. Both teams beat (or project to beat) the Bills, Dolphins, Colts, Jaguars, Redskins, Giants, Cowboys, and each other (at 11 projected wins each, we can discard both); the Patriots also beat the Bills (a second times), Texans, and Steelers; the Jets also beat the Dolphins (a second time), Titans, and Browns. Assuming that the Patriots extra opponents lose out, and the Jets opponents all win out, we can calculate their relative strength of victory (none of the extra opponents on each side play each other, although the Titans play both the Texans and Patriots, Miami plays the Patriots, and Buffalos takes on the Jets). The Bills (6 wins), Texans (6) and Steelers (8) give the Patriots 20 net strength of victory points; the Dolphins (5+3), Titans (3+3) and Browns (3+3) also give the Jets 20 net strength of victory points. If the Dolphins had won, the Jets could still achieve 21 net strength of victory, so the Patriots wouldn’t be able to clinch yet. Instead, we move deeper into the tiebreakers.
The sixth tie breaker is then strength of schedule. Twelve of the games are against common opponents, so will have an identical strength, and two more games are head-to-head (so have the identical strength, or we wouldn’t be in tie-breakers). We only have to compare the substitution teams. The Patriots have the Steelers (8), and the Broncos (11+1, because they will have to have beaten the Steelers in Week 15 in this scenario) for 20 net schedule strength points. The Jets have the Browns (3+3) and the Raiders (6+3), for a maximum of 15 net schedule strength points.
The NFL finally got to use half of its tie breaking steps. Maybe someday we’ll see the coin toss at step 12.