Sport: The Big If

"It's a tough field," said World Champion Racing Driver Juan Manuel Fangio. as he looked over his competition at Florida's "International Twelve-Hour Grand Prix of Endurance." "But if my car holds up I can win."

The rapid Argentine was being remarkably casual with a big if. In all the Grand Prix circuit (including Le Mans. Italy's Mille Miglia and Britain's Grand Prix at Silverstone), no course is tougher on cars than the 5.2-mile tangle of flat-turn runways and taxiways at Sebring's abandoned airfield. Drivers have to hit the brakes and shift down at...