I hope Peter King of SI.com has a chance to read this. Recently, Pete posted an article on Monday Morning QB concerning the new overtime rules. One of the points of his article reads,
4. The more-exposure-to-injury argument, really, is bogus. On average, the NFL plays 12 overtime games a year. That means a team has a 75 percent chance of playing an overtime game in an average year. And with more games now being won on the first possession of overtime (34 percent of games since 1994 have been won by the coin-flip winner on the first possession, compared to 25 percent in the earlier era), half of your team isn't going to take the field for a third of the OT games anyway.
I just thought I'd point out that a given team does not have 75% odds of playing in an overtime game each season. Here's the logic.
There are 256 total football games played in an NFL regular season, and we are assuming that 12 of these games will go to overtime. It is much easier to determine the odds that your team DOESN'T play in an overtime game. We do this by determining how many ways the 12 overtime games can distribute themselves among the 240 football games that your team ISN'T playing in.....
(240 * 239 * 238 * 237 * 236 * 235 * 234 * 233 * 232 * 231 * 230 * 229) = LINE 1
and dividing this huge number by the total number of ways the 12 OT games can distribute themselves in all 256 games played.....
(256 * 255 * 254 * 253 * 252 * 251 * 250 * 249 * 248 * 247 * 246 * 245) = LINE 2
So by dividing LINE #1 by LINE #2, we obtain a 45.28% chance that your team DOESN'T play in OT, which means each team has a 54.72% probability of playing in at least one overtime game each season.