There’s an old sports adage that argues that coaches get too much blame for bad results and insufficient credit for good ones, and Denver fans have witnessed both sides of this paradox over the past few years. Broncos’ head coach Josh McDaniels was branded a boy genius last fall when he won his first six games, but then fell back to earth when the Ponies finished with a disappointing 8–8 record and missed the playoffs. This season, media and fans will scrutinize Coach McD through an intensified microscope, and if the team muddles through another nonplayoff season, his putative brilliance will be debatable, at best.

Over at Coors Field, Jim Tracy was the savior who took over the moribund Rockies in June 2009 and led the team to the postseason. As of this writing, however, and despite producing essentially the same statistics as 2009, the Rockies have struggled to stay very far above .500. Even if the team makes yet another late-season charge, you can bet Tracy—who’s been let go twice before, by the Dodgers and Pirates—will be jettisoned again someday, probably for reasons he can’t begin to control.

The 2009–2010 Nuggets offered the best example of a great coach’s impact. For most of last season the team rolled, widely pegged as a legitimate threat to the reigning champs, the Los Angeles Lakers. But when coach (and likely hall-of-famer) George Karl left in March to fight neck and throat cancer, top-job neophyte Adrian Dantley stepped in—and the Nuggets simply crumbled, whimpering out of the playoffs in the first round. The lesson? Most coaches are mere caretakers who have little impact on their teams’ fortunes, but the elite ones are truly irreplaceable. Denver, it seems, is still sorting out which of its sports leaders is which.