Warren Buffett and truck-stop mogul Jimmy Haslam are fighting over a seemingly obscure accounting method. What’s really at stake: possibly as much as $1.2 billion.

Buffett of course is chairman and chief executive of Berkshire Hathaway. Haslam, who owns the Cleveland Browns football team with his wife Dee, built his father’s truck-stop chain, Pilot Travel Centers, into an empire before selling a majority stake to Berkshire.