It didn't pay off.
The big number was 29 minutes, the gap between Grevers' winning his Olympic 100-meter backstroke semifinal and the start of the 400-meter freestyle relay final Sunday night.
The odds were he couldn't have gotten the backstroke out of his legs. The odds were he wouldn't have swum 100 meters of freestyle fast enough to have kept France from extracting delicious, ironic revenge on the United States for what had happened in the same Olympic relay four years ago.
But, as Grevers suggested a few minutes before the relay began, who knows?
"It's the Olympic final," he said. "You have adrenaline to wash away all that lactic acid. I have a feeling all those guys (in the final) are going to beat me, though. That's what I'm praying. If they don't, that's the gamble we took, and I think it's what we need to do."
This isn't about controversy. There wasn't any, because Grevers didn't try to stir it. He was comfortable with the decision to not have him in the final.
The Lake Forest and Northwestern grad hadn't convinced the coaches otherwise in the morning relay prelim, during what assistant coach Eddie Reese said was "show-and-tell time."
Grevers' split, 47.54 seconds, was second fastest of anyone in the heats. But he felt he needed to clock 47.3 and for the gap between his backstroke and relay prelims in the morning to be bigger, some 40 minutes, for him to make the convincing case for inclusion in the U.S. final four.
"I don't think I could have gone any faster than the morning," he said. "But if there is someone right next to you, you never know."
This is how it played out in the final.
You don't count the time of the leadoff swimmer, Nathan Adrian, who lacks the advantage of a flying start. The final two U.S. swimmers, Cullen Jones (47.60) and Ryan Lochte (47.74) were slower than Grevers had been. French anchor Yannick Agnel (46.74) ran down Lochte in the final meters, just as U.S. anchor Jason Lezak had done to Frenchman Alain Bernard in 2008.
The difference in the end was .45 seconds. Taken as straight math, the difference between Grevers' morning time and Lochte's evening time would not have been enough to close that gap.
None of the four U.S. swimmers from the morning swam again in the evening. Adrian and Jones, the top two finishers in the 100 at the U.S. trials, were expected to be in the final. So were the two swim superstars, Lochte and Michael Phelps, even though neither swam the event at the trials. Relay choices are at coaches' discretion.
So Phelps gets his 17th Olympic medal, one short of Soviet gymnast Larissa Latynina's all-time record, after a sparkling split of 47.15. Grevers gets his fourth Olympic medal for swimming the prelims.
And now Grevers moves on to Monday night's backstroke final, where he is the favorite, where he thinks he can also break the world record.
That looks like a pretty good bet the way Grevers swam Sunday, when he broke 53 seconds twice (52.92 in the heats, 52.66 in the semi) and was the only one to do it. He knows another Frenchman, reigning world champion Camille Lacourt, probably was holding something back for the final.
"Just because I'm in the lead now doesn't mean it's going to be easy (Monday)," Grevers said.
At the Olympic trials, he had become the second fastest ever in the 100 back, his time of 52.08 trailing only retired U.S. swimmer Aaron Peirsol's 51.94. Grevers wants that record. He thinks it will take the perfect race to get it.
Maybe not swimming that relay leg will make such perfection possible. It gave him the chance to do a full warm down after the backstroke. He didn't need to swim two races in about 30 minutes. (Lochte swam a 200 freestyle semi about 80 minutes before the relay.)
"At the Olympic level, that's something Phelps can do, and Ryan can do, and almost no one else in the world can do," Reese said.
And Matt Grevers? We'll never know.