The only explanation is that Rick Carlisle was slipping motor oil into Joe Dumars' coffee. Or got caught red-handed stealing all the green M&Ms out of owner William Davidson's private stash. Or, despite being warned to cease and desist, continued to run up and down the Pistons' practice floor late at night in golf spikes.

	Rick Carlisle got the most out of the Pistons in posting back-to-back 50-win seasons.

Even if he was guilty of all the above hypothetical transgressions, there are more than a few NBA teams who would put up with all that if their coach did what Carlisle did in Detroit, which is take a losing culture and a mediocre roster and produce back-to-back 50-win seasons and a trip to the Eastern Conference finals.

What ESPN.com asked me to do in this column is explain why Carlisle was called at his vacation home in the Carolinas Friday night and fired with a year left on his three-year contract. Truth is, I can't. Sure, I can tell you I've been told managing partner William Davidson, team president Tom Wilson and basketball operations president Joe Dumars felt Carlisle was too rigid in how he dealt with the front office as well as his playing rotation. Or that the Pistons probably would've hung with Carlisle for the final year of his contract if Larry Brown hadn't become both available and amenable to moving to Detroit. And that the postseason performances of rookies Tayshaun Prince and Mehmet Okur drew criticism that Carlisle should have had them in his rotation the entire season. Carlisle also had a couple of vets in the locker room privately questioning his adjustments and playing-time distribution.

But fire the guy? After only two years as a head coach? After winning Coach of the Year his first season and directing a team with clearly less talent than the Pacers, Raptors, Hornets, Celtics and Nets -- and arguably Magic and 76ers as well -- to the Eastern Conference's best record? A guy who, while reluctant to play Prince after he stumbled mightily in a stint of five starts early in the season, rode him to advance to the East finals? A guy who allegedly is human kindling (stiff and dry) yet not only bravely attended his firing announcement -- name the last coach to do that -- but joked that the guard almost didn't let him in and then graciously thanked everyone in the organization for giving him a chance? A guy who called every voting member of the media to tout his players for the annual league-wide awards and provided his cell phone number should they have any questions?

In any case, don't count Defensive Player of the Year Ben Wallace among those who feel Carlisle didn't go with the rookies soon enough. "I think he did the right thing," Wallace said. "We won 50 games this season and last season. It's tough to go away from what works for that long. You have to take your time making changes, especially when you have the kind of team we have."

	“	I think it was definitely a learning experience for (Rick Carlisle). But why shouldn't it have been? He was a second-year coach. ”
		— Cliff Robinson

Cliff Robinson saw Carlisle grow as the postseason progressed. "I think it was definitely a learning experience for him," Robinson said. "But why shouldn't it have been? He was a second-year coach. I definitely saw him getting more comfortable making adjustments as we went on."

Not playing rookies is a beef that has been levied at a legion of top-caliber coaches over the years. No rookie is ever ready to play NBA-caliber defense and few are ready to play a complementary offensive role. My belief is that Prince and Okur were better players for having to earn their minutes at the defensive end and that their effectiveness came, in part, because they spent all that time practicing together on the Pistons' second unit. Squawking from the far end of an NBA bench is so routine it barely deserves mention.

As for Brown succeeding Carlisle, well, there's no reason he shouldn't be more successful -- if indeed he does show, which will remain a question mark until Monday. Brown inherits a disciplined defensive-oriented team with loads of playoff experience that will fill one of its biggest holes at either power or small forward, courtesy of the No. 2 pick in this year's draft. Rest assured that Brown will be more offensively creative than Carlisle, routinely changing his playbook so often he has to recycle names for his plays. Also be sure that he will want to overhaul his roster just as quickly if the team is not meeting his expectations.

Brown, you see, isn't long on patience. Then again, clearly the current Pistons aren't, either. Sounds like they were made for each other.

Ric Bucher covers the NBA for ESPN The Magazine. E-mail him at ric.bucher@espnmag.com. Also, send a question for possible use on ESPNEWS.