Then CalBear's stats are irrelevant. Why is it that his stats on going for it on 4th down up 9 "prove" his point but my stats of NFL coaches *never* going for 2 first in the down by 15 situation just show that the coaches are wrong and the stats are invalid.
I am certainly not asserting that coaches always take the best option to help their team win; in fact I'm sure that's not true.However, I think it's highly unlikely that going for it on fourth down leading by 9 is significantly better for your team than going for it on fourth down leading by 8. Here's a scenario:
* Trailing team kicks off, you run three plays, and now it's fourth and one on your own 25 with 5:00 left. Punt or go for it?
If you go for it, success will give you another series, which will take 2:00 off the clock; if you punt, you move field position by about 35 yards. So the three possible results are:
1) Success. First and 10 at own 26. Most pertinent result, fourth down at own 30ish, 3:00 remaining.
2) Punt. On defense, first and 10 at opponent's 40.
3) Failure. On defense, first and 10 at own 25.
For your assertion to be correct, two things must be true: Result 1 must be
significantly more valuable to the leading team than Result 2, because Result 3 is extremely bad. And, Result 1 must be
significantly more valuable to a team up by 9 than a team up by 8.
The first part is necessary to make going for it the correct decision. The second part is necessary to make the knowledge of being up by 9 vs. up by 8 meaningful to the leading team.
Frankly, I don't think either part is correct; I think the risk of scenario 3 is high enough that punting is the correct decision for the leading team, whether up by 9 or up by 8. And I don't think that being up by 9 makes it a better choice than being up by 8; do you really want to risk giving a team down by 9 the ball already in field goal range?