On Saturday night, while most basketball fans were watching the Final Four, the NBA playoffs got under way. Not officially, of course. That doesn’t happen until April 16. But for the Detroit Pistons, Chicago Bulls and other teams fighting for the bottom of the brackets, the postseason already has started. Detroit’s 94-90 victory at Chicago on Saturday wasn’t quite a Game Seven. The Pistons aren’t quite home free just yet, and the Bulls aren’t quite dead. But it sure looked an awful