Detroit — NASCAR does not race in the rain. Too dangerous with the speed on the big ovals.
IndyCar does, but only on street and road tracks.
Formula One races all over the world in the rain. Often the results are either famous or infamous.
On Belle Isle Saturday, race winner Carlos Munoz and second- and third-place finishers Marco Andretti and Simon Pagenaud benefited from fortunate decisions about when to change from rain tires to the normal, slick racing tires, and when to change them back when the conditions change yet again.
But they sealed the deal after the decisions by driving on a somewhat wet track with no tread on their tires.
They and the other 20 drivers in the field might need to navigate a soaked circuit again Sunday to win the second Dual in Detroit. And cooler temperatures might make the driving all the more perilous.
"When Marco and Simon and I remained on the track for longer than anyone else, it was quite tricky, especially in Turn 1 and Turn 2. It was really wet," said Munoz, who won for the first time in the IndyCar Series, in the rain-shortened event.
He said his team owner, Michael Andretti, the former driver and member of the legendary racing family, had offered sage advice before the uncommon day of racing began.
"Michael said before the race, you're just going to have to keep your nose clean and you will have a good race. And that's what I did," Munoz said. "I wasn't going too fast when the condition was tricky.
"But, you know, in the end, I had like a 30-second margin, so I just had to cruise to the finish line."
Rain makes a dangerous sport more treacherous.
On dry racing surfaces drivers often purposefully slide, at least a tad, when tires revolving with considerable speed lose just enough grip to help carry speed through the corners.
Skids at high speed, no matter how minute, require skillful sensitivity at the controls.
When the racing surface is wet, maintaining pace requires enormous expertise. Winning in the rain? Sometimes it involves wizardry.
In the rain, stars are born, racing legends are made.
Ayrton Senna, the late, great Formula One racer whom many deem the best driver of all time, was brilliant on wet tracks.
Senna's drive in the gloomy wet at Monaco in 1984 introduced his genius to the racing world.
In Portugal the following year he planted the seeds of legend, again in the rain.
In 1993, at Donington Park in Great Britain, Senna drove an opening lap in a shower that is often judged the best lap in the history of motor sport. Starting from fifth, he passed Michael Schumacher, Karl Wedlinger, Damon Hill and Alain Prost — all on one lap — to take the lead.
Schumacher, Hill and Prost all were Formula One champions.
From that moment, one lap into the race, champions or not, pursuing Senna was futile.
Schumacher also was fabulous in the rain, often passing others as if he, alone, was on a dry track. Jacky Ickx seemed to sail right through puddles.
For most drivers, however, the rain is a pain.
It can make cockpits wet, including shoes on the pedals. It can drastically reduce vision, especially after the first few cars, when the spray and rooster tails produced by the high speeds make the track ahead vanish.
Rain forces the juggling of strategies.
Decisions about when to pit for changing from racing slicks to rain tires, and maybe back again when the rains stops, force racing teams to work beyond the realm of meteorology to superhuman perception.
Or, maybe it is just good luck.
A mistake on tire strategy can quite literally mean the difference between first and last.
And getting it right got Munoz his first Indy win, a second place for Andretti, and a third for Pagenaud, of Team Penske.
They and their teams got the tires right.
But Munoz, Andretti and Pagenaud did the driving.
Pagenaud agreed risking slicks too soon on the wet surface can be like driving on egg shells, requiring delicacy and speed simultaneously.
"Obviously, staying on dry tires in the wet conditions is always tricky," he said. "But you can gain 3 to 5 seconds on someone else who is on rain tires on a dry track."
Andretti was the first driver to go to the slick tires on Lap 9, when the track still looked wet and some drops still fell amid cracks in the clouds that let some sun shine through.
He had to debate his team to get it done, he said.
And then he had to prove he could handle a track still wet, at high speeds, with no tread on his tires.
"The only time it's a mistake is when you're in the fence," he said, after picking up his trophy for second place. "The goal was just to keep it going forward.
"But there was plenty of dry line, and I knew I had two laps of yellow (after he pitted to change to the slicks) to get plenty of temp in the tires. And it really worked out for me because we went green for a couple of laps and then when there was a yellow. I was the only one who had temperature I my tires again. So it worked out."
Andretti said he has occasionally made a mistake in his career by pitting too early and having to drive too slowly until the track dried.
But he said he has never wrecked as a result of the decision.
"I've gotten bit by doing it too early, just on the pace. I haven't crashed it, but the goal really is to just keep it off the fence.
"Today I was asking for pace all the time to see if I was up there," he said, of gauging the dryness of the track. And once it came in, it was game on."