The conviction of former WorldCom chief executive Bernard J. Ebbers makes one thing perfectly clear: If you're planning to be an incompetent CEO at a company playing fast and loose with the rules, you'd better be extremely good at your incompetence. The jury that convicted Ebbers yesterday of nine counts growing out of the $11 billion accounting fraud that bankrupted the telecommunications giant just didn't believe such massive fraud could be going on under his nose without his knowing anything about it. If they had, Ebbers might have gone down in history as the industry's most clueless CEO, but he also might be free of criminal conviction.

The case hinged on whether the jury would believe Ebbers could have had such a close relationship with former CFO Scott Sullivan that they met several times a day, without ever comprehending that Sullivan was executing enormous illegal financial maneuvers. If Ebbers hadn't a clue, it meant his CFO was a better liar than he was a CEO. And the jury decided that, despite testimony about the breadth and brazenness of Sullivan's lying, Ebbers ultimately wasn't incompetent enough for that story to make sense.

Sentencing is set for June 13. The convictions could give Ebbers, who is 63, a sentence of as long as 85 years, although observers believe around 20 years to be more likely result. That's plenty long enough to make clear to CEOs, whether in telecommunications or other industries, that if their incompetence isn't world class, then their competence had better be.