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Steelers & I
01-13-2009, 04:24 AM
http://www.pro-football-reference.com/blog/?p=458

I found "SOME" of the information in this article to be a bit interesting.





Itís hard to beat a team three times in a season
Posted by Doug on Tuesday, January 8, 2008

An email from a good buddy of mine (and occasional commenter here):

i am so sick and tired of hearing ďits so hard to beat a team three times in a seasonĒ. idiots. yes, going 3-0 vs a playoff team is hard. BUT NOT IF YOU SPOT TEAM A TWO GAMES YOU MORONS.

Heís right, of course. This is essentially the same reason why black isnít necessarily a good bet on a roulette wheel thatís come up red on the last ten spins. Yes, itís incredibly unlikely for a wheel to land on red on eleven straight spins, but given that itís already landed on red for the last ten spins, itís not at all unlikely for it to land on red for the eleventh. Likewise, before the season, the Cowboys beating the Giants three times would have been something of a longshot. But now that theyíve already done two-thirds of the work, itís not.

Anyone making the hard-to-beat-a-team-three-times claim probably is suffering from a failure to understand conditional probability, but that doesnít necessarily make them wrong. Football games are not roulette wheels. In particular, theyíre not independent. Maybe teams learn more from losses than from wins, or something like that, and it really is hard to beat a team three times, even if youíve already beat them twice. Thatís an empirical question. Letís check it out.


Since the merger, there have been 17 instances of a team trying to beat another team thrice in a season. In 11 of those cases, the team succeeded. Teams, like this yearís Cowboys, who have the better record and were therefore playing at home, are 9-3 when trying to beat a team three times in a season. Hereís the data:

+------+-------+-----------+-------+-----------+-----+-------+
| year | team1 | t1_record | team2 | t2_record | loc | score |
+------+-------+-----------+-------+-----------+-----+-------+
| 2004 | GNB | 10-6-0 | MIN | 8-8-0 | H | 17-31 |
| 2004 | STL | 8-8-0 | SEA | 9-7-0 | R | 27-20 |
| 2002 | PIT | 10-5-1 | CLE | 9-7-0 | H | 36-33 |
| 2000 | NYG | 12-4-0 | PHI | 11-5-0 | H | 20-10 |
| 1999 | TEN | 13-3-0 | JAX | 14-2-0 | R | 33-14 |
| 1998 | DAL | 10-6-0 | ARI | 9-7-0 | H | 7-20 |
| 1997 | NWE | 10-6-0 | MIA | 9-7-0 | H | 17-3 |
| 1997 | GNB | 13-3-0 | TAM | 10-6-0 | H | 21-7 |
| 1994 | PIT | 12-4-0 | CLE | 11-5-0 | H | 29-9 |
| 1994 | MIN | 10-6-0 | CHI | 9-7-0 | H | 18-35 |
| 1993 | RAI | 10-6-0 | DEN | 9-7-0 | H | 42-24 |
| 1992 | KAN | 10-6-0 | SDG | 11-5-0 | R | 0-17 |
| 1991 | KAN | 10-6-0 | RAI | 9-7-0 | H | 10-6 |
| 1989 | HOU | 9-7-0 | PIT | 9-7-0 | H | 23-26 |
| 1986 | NYG | 14-2-0 | WAS | 12-4-0 | H | 17-0 |
| 1983 | SEA | 9-7-0 | RAI | 12-4-0 | R | 14-30 |
| 1982 | MIA | 7-2-0 | NYJ | 6-3-0 | H | 14-0 |


Notice that the teams with LESS THAN 6 LOSSES were ALL successful in winning the 3rd meeting of the season.