Fernando Alonso says Aston Martin did not expect so much rain to arrive at the Monaco GP when they pitted for new dry tyres just before a downpour.
Alonso was running in second behind Max Verstappen when rain caused chaos and pitted for the medium tyres on Lap 55, just as the weather became worse.
He was forced to pit again on the next lap for intermediates, while Verstappen was able to make just one pit stop, enabling the Dutchman to go on and win the race by nearly 28 seconds.
Had Aston Martin opted to go straight on to intermediate tyres, Alonso would have been better placed to end Red Bull's winning run in 2023, but the Spaniard explained why the dry tyres were selected again.
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"When I stopped, it was just raining in Turns Five and Seven. The rest of the track was completely dry," Alonso told Sky Sports F1.
"If you are in P2 and put intermediates on for only two corners, maybe Jenson (Button) could guess that good!
"The forecast we had was just a small shower and a few drops of rain. We didn't expect that amount of rain."
He added: "For me, it was very clear that the track on that lap we stopped was completely dry apart from Turns Seven and Eight. So how I will put on the inters? It was completely dry 99 per cent of the track.
"So I stopped for dry tyres, the weather forecast was a small shower and a small quantity of rain as well what we had as a team, and we had a lot of margin behind us you know to put the dry tyres and if necessary, the inter tyres. So, you know, maybe it was extra safe, I don't know.
"That minute and a half that it took to go through Turns Five, Six, Seven and Eight again it changed completely so the out lap on the dry tyres it was very wet when I got to those corners but the lap that we stopped, it was completely dry."
Horner: Alonso making right call would have put Red Bull under pressure
Verstappen was 12 seconds ahead of Alonso when the rain intensity increased and appeared to be in control.
However, Christian Horner feels Red Bull would have faced more pressure had Aston Martin put intermediates on Alonso when he first stopped.
"It felt as though we'd gone a lap too long before going on to the inter and had Fernando picked the inter it would have been much tighter and put more pressure on our pit stop," Horner told Sky Sports F1.
"Thankfully he took the slick tyre just as the rain was growing and at that point it was important Max didn't take any risks and got it to the pits.
"When you're the lead car you can only lose, you have nothing to gain. You've just got to try and work with the conditions - we have spotters out there, you're trying to look at the radar, looking at the crowd - and just trying to piece it together. The driver has the best knowledge of what's going on on the circuit."
Alonso: Verstappen's amazing pace negated Aston Martin's strategy
Aston Martin had made a strategy gamble at the start of the race by starting Alonso on the front row with the hard tyre, while Verstappen and Esteban Ocon behind started on the grippier medium tyre.
That decision meant Alonso could not really contest for the lead off the line and the two-time world champion said Verstappen's ability to then run his medium tyres for so long negated Aston Martin's aggressive strategy.
Asked if he could have won had the race stayed dry, Alonso said: "I think we didn't have a chance to be honest. I think we were brave and the strategy is not normal that you start on the first row of the grid and you choose the hard tyre. I tried to do the opposite of the leaders.
"And that shows you know the commitment from the team and how aggressive everyone was in Aston Martin to try to get the win.
"We knew that it was some downside that the strategy we could end up maybe P5 or P6 something like that out of the podium. But this morning we discussed and we said you know we had couple of podiums this year, so we go for all or nothing. We start on the hard tyre and we didn't have the pace. That was the only problem we had in the race.
"I think the strategy was good. The medium tyre was behaving surprisingly good. In our opinion we were hoping for more graining or bigger degradation. Max was able to drive 50 laps in an amazing place and that was the reason why he won the race, not because the strategy, he was just faster than us."
Alonso not giving up on title hopes
Alonso is 51 points behind Verstappen ahead of his home event, the Spanish Grand Prix, and 12 points adrift of Sergio Perez, who failed to score in Monaco.
The Spaniard thinks in previous seasons he would be leading the championship after six rounds, having finished on the podium five times, and fourth in the other race.
"I think in any of the seasons that I remember, back in the 2000s I would be leading in the championship with the results that I got this year," he said.
"But now, there's Red Bull and Max dominating in every race, and even with great results you're just stepping behind them. We didn't have the best car in 2010, [but] we arrived leading the championship in Abu Dhabi.
"We didn't have the best car in 2012, and we still fight for the championship until the last lap in Brazil. So the championship is long. We will not give up.
"We will need weekends where Red Bull has some issues, like Sergio had here with zero points. If Max has one or two of those, we will be a little bit closer in the championship. This is motorsport, anything can happen, but on pure pace I think we don't have the chance yet. But we will not give up."
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