Just curious? Who made that argument? I think many of us have said that no coach goes on to be successful in a job without winning more than the previous coach within the first two years... almost always in the first year.
The comparison isn't really of the coach compared to himself but the coach compared to his predecessor.
Your numbers are interesting and meaningful at 70% accuracy. I believe the % of coaches who fail to succeed in a new job that do NOT improve the team record over the previous coach within the first two years is higher than that.
Let me address this head on.
I cannot show you data that
proves a coach will succeed any more than you can show me data that
proves that a coach will fail. This conversation was not about that to begin with, it was about looking at coaches who are
perceived as successful and seeing what that means compared to talent and the delta in record.
Next, I cannot chase the bolded statement as it is too vague, nor should I. The burden is on you to provide data that counteracts anything that I have said, and nothing you have said counteracts my data.
Feelings/beliefs without data, are not data. I cannot stress that enough.
That aside, let us work the problem.
First, define "fail to succeed." This is important as you could be measuring nothing more than fan/administrative discontent or lack of reasonable expectations. Does a coach being fired prove that he wouldn't have succeeded, or does it just prove he didn't in the time he was given? Is your paradigm for success national championships, or just improving the record?
Second, if your paradigm is winning national championships, I can help you narrow your search results down significantly. What I have found, going back to 1993, is that coaches who have won national championships took, on average, 6 years to do so (3 if you adjust out two of those coaches who averaged 19 years until their first, but who then won multiple national championships [Bowden/Osborne]). Next, not only did it take an average of 6 years, but it takes an average of recruiting in the top 15 to win (at least going back to 2005 which is far as my recruiting data can take me).
So as I understand your question, it would better be restated like this: How many coaches didn't win a national championship, were given 6 years to do so, and averaged top 15 recruiting over their tenure? Find coaches who fit that paradigm over the past 20 years (as that seems to be an important timeline for you) and let's discuss that data. Otherwise we might be measuring all sorts of factors well outside a coaches control and potentially drawing incorrect conclusions from that.