Bob Carlton watched the pace car peel off and the 43 cars that were clumped behind it roar into full throttle. It was always a thrilling sight—they were packed tighter than minivans in a Wal-Mart parking lot. He studied their first lap of jockeying, then hunched over to fiddle with the knobs on his scanner. He took his sunglasses off—not easy with headphones on. Once he had settled on the right frequency, the banter from the booth filled his ears. But a few minutes later, he shut it off. He couldn’t enjoy it, and anyway he needed to think.

A version of this article appeared in the April 2006 issue of Harvard Business Review.