The FIM had decided by 1989 that there could be no more than two starts and that after the second race, started on slicks, was stopped due to rain, the race would be deemed complete.
In an interesting footnote, the 1989 Belgium Grand Prix in Spa Francorchamps, scheduled for 18 laps and 73.3 miles, was entered in the books as a “complete” eight-lap, 34.5-mile sprint race victory for Eddie Lawson. But if you look at the old magazines you’ll see Kevin Schwantz celebrating the victory atop a wet podium and John Kocinski standing third in his 500 debut.
In fact, the race director, fearing a riot if he sent the fans home after only seeing two aborted starts and eight recorded laps, decided to appease the crowd by sending the riders out again even though it was clearly against the rules. Word was that the “promoter” ordered the race director to do this. The “promoter” was Bernie Ecclestone. Eventually half points were awarded and the FIM realized that something had to be done.
Thus the “wet race” and “dry race” rules were instituted. Under these rules if a race starts in the dry with riders on slicks and rain begins to the extent that the race director believes that there is insufficient traction for slick tires, he orders red flags. If three or more laps have been run, the original race distance, minus the number of laps run and minus one additional lap, is established for the second leg. However, regardless of the conditions at the start of the second part, the race is declared “wet,’ meaning that it would not be stopped simply because it begins to rain. Riders go out for part two with the understanding that, if they opted for the wrong tires, they either have to wobble around like Steve Manship at Silverstone or come in for a change. The final results are then to be based on aggregate times.
This worked from the late eighties until 2003 when Dorna, protecting their TV coverage against long delays, overrode strong MSMA (Motorcycle Sport Manufacturers Association) objections and managed to introduce the first of three variants of “flag to flag” racing -- races which would not be stopped and restarted due to rain.〔Noyes, Dennis: (''Time to Fix 'Flag-to-Flag' Pit Stops Before Luck Runs Out'' ) SpeedTV.com 20 September 2006.〕