This is how Alonso could indeed have won the Monaco Grand Prix

Did Aston Martin blunder?

Alonso came in for medium tyres at the end of lap 54. At that point it was already raining pretty hard, but apparently not hard enough for Aston Martin to put the Spaniard on rain tyres. A lap later, Alonso was then still brought in, but this time for intermediates.

Yuki Tsunoda was slightly ahead of Alonso in the pit lane when the Spaniard changed to mediums, but the AlphaTauri driver did change to intermediates, unlike the two-time world champion. This makes Tsunoda a good reference point for what could have happened, should the Aston Martin driver have changed to rain tyres. Indeed, you can assume that Alonso would have been just as fast, or probably even faster, than the Japanese.

Tsunoda much faster than Verstappen

At the time Alonso came in for his new slicks, Max Verstappen was still outside on old medium tyres. At this point, Tsunoda was already driving on intermediates and the Japanese was much faster than Verstappen. Tsunoda posted a time of 47.660 seconds in the second sector, while the Dutchman took a whopping 55.513 seconds here. A difference of almost eight seconds!

Even in the first sector, Tsunoda was already faster on his intermediates than Verstappen on slicks, despite the AlphaTauri driver having made a pit stop. Here, Tsunoda was some seven-tenths faster than the Red Bull driver. That meant Tsunoda was already over eight and a half seconds faster than Verstappen through the first two sectors.

Could Alonso have won?

On lap 54, when Alonso entered the pits, his gap to Verstappen was 8.3 seconds. So with Tsunoda's first and second sectors, Alonso would have been ahead of Verstappen. To know for sure whether Alonso would have been in front of Verstappen with Tsunoda's pace, it takes some further calculation.

Alonso comes out of the pit lane 26 seconds behind Verstappen. On mediums he barely catches up, but would he have managed to do so on intermediates? Assuming Alonso drives the first two sectors as fast as Tsunoda, he gains 8.5 seconds there. In the final sector, partly due to Verstappen's pit stop, Tsunoda gains 21.027 seconds. Add to this the 8.5 seconds and so Verstappen would have lost 29.5 seconds to Alonso on exiting the pits.

This would have been enough for the lead in the race. Indeed, as mentioned, Alonso returned to the track 26 seconds behind Verstappen after his pit stop. Had Alonso been as fast or faster than Tsunoda on the intermediates, and we can pretty much assume that Alonso would have taken the lead by three seconds.