I actually think you're starting to come around.
If roughly half of all coaches win in their first season, and of the remainder almost half win in their second season, then your chances to win with a new coach are over 50%. If you don't start winning until year three, your chances of winning are less than 50%. The data set is really low on this next one, rendering it anecdotal at best, but GMs who stay with coaches that haven't won yet always end up replacing them in the next two seasons.
And I know you are poised with all kinds of "but this time it's different!" arguments, to which I can only respond, "they're all different." In essence based on history we're more likely to be successful if we go in a new direction. Sure, there's a chance Rivera is successful, and he leads us to a decade of dominance. But it's probably just as likely as a player coming back successfully from three ACL surgeries on the same knee.
No I am just looking at the stats from a different perspective. You say half of the coaches since 1992 were successful in their first year. I just looked at current coaches for all 32 teams ( I included the just fired coaches since they haven't been replaced) and what I found is that 8 of the 32 coaches had a winning record in year 1. That means 75% of the coaches didn't win in the first year. Lets assume that without looking it up 50% of the coaches had a winning record in the second year. What that still doesn't address is that many of these coaches didn't necessarily build a successful program after that. Plus it doesn't include guys like Hue Jackson for the Raiders who was given only 1 year to succeed. So if we are looking for a guy who will win in the first 2 years irregardless of how they do down the road then lets can Rivera and go elsewhere. And we can do that over and over just like the Raiders until we find someone.
But what about the guys who won in year 1 or 2 and then struggled down the road?? For example Rex Ryan started off great guns at 9-7 and 11-5 his first 2 years. Since then 8-8 and 6-10. Given your criteria he is a proven guy who built a successful program. The reality is he is like Fox when he was here, he had some good years and some bad years. How bout Whisenhunt- he went 8-8 in year 1 and 9-7 in year 2 and 10-6 in year 3 and a Superbowl appearance. Successful guy right?? How about the last 3 years- 5-11, 8-8, 5-11. Yeah successful program.
I could go on and on.
The reality is your criteria is hardly a reason to fire Rivera based on selective stats. The vast majority of current coaches and just fired coaches were not successful in year 1 and even though more were successful in year 2, that didn't necessarily guaranteed future success.
So the notion that if you don't win early you won't win needs a sidebar which states that even if they have been successful in year 1 or 2 doesn't mean they will be successful in future years. Some will and some won't. Look at the current coaches.
As for going back and forth don't expect me to take your position. If I thought your argument had merit I would have agreed to begin with. And since I am at work won't have time to do a bunch of research. I had a no show this hour hence the postings.