Beware of regression to the mean
When new coaches have success, they usually don't deserve all the credit
Every year, across all sports, a handful of coaching changes seems to trigger sudden, sharp team turnarounds. Fans inevitably react to these reversals of fortune by crediting the new guy's discipline and smarts ("Jason Garrett really brings out the best in the Cowboys ") while questioning athletes' commitment and heart under the old guy ("But man, the team must really have been mailing it in for Wade Phillips").
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