Christian Horner knows exactly where things went wrong for Red Bull F1

The RB19 has been a dominant force on the grid during the 2023 F1 season, with Red Bull's challenger last year going down in the record books as the most successful car in the sport's history, with Max Verstappen and Sergio Pérez winning a record-breaking 21 of the 22 Grand Prix last year.

But this year is a very different story, and team principal Christian Horner has pinpointed what went wrong for Red Bull.

Oscar Piastri won the Azerbaijan Grand Prix on Sunday, a victory that, along with Lando Norris' fourth-place finish, propelled McLaren to the top of the F1 Constructors' Championship standings and also put Red Bull in uncharted territory by finishing second for the first time since the start of the 2022 season.

After the Azerbaijan Grand Prix, Horner recognised that the 2023 Spanish Grand Prix was the moment things went off the rails. German Outlets Automobiles, Motors, SportsHorner pointed to the upgraded floor the team brought to Barcelona last season as the moment the development of the RB19, and then this season's RB20, went awry.

“If we look back at the history of our development we can see that the first mistake was the underbody upgrade at Barcelona 2023,” Horner said on Sunday.

This point becomes even clearer when comparing the data for 2023 and 2024. Take the Baku City Circuit, site of last weekend's Azerbaijan Grand Prix. In 2023, the race took place at the start of the season (before the Spanish Grand Prix) and saw Red Bull sweep the front row with Perez winning and Verstappen coming in second.

At the 2023 Azerbaijan Grand Prix, Verstappen's best lap time was 1m44.232s, set late in the race on the old hard tyre. But on Sunday in Baku, Verstappen's best lap time was 1m46.798s, also set on the old hard tyre.

Comparing the two laps, Using telemetry data F1 TempotThe RB19's dominance is astounding: Verstappen's 2023 best laps are shown in white, his 2024 best in blue.

Comparing Pérez's best laps in 2023 to 2024, the advantage is less pronounced, but his 2023 effort is still superior. His best lap in 2023 was a 1m44.589s on worn hard tyres. At Sunday's Azerbaijan Grand Prix, Pérez's best lap was a 1m47.013s, also on worn hard tyres, just before a crash with Carlos Sainz Jr. took both drivers out of the race.

Why didn't Red Bull realise this sooner?

It may depend on Verstappen's talent.

He won the 2023 Spanish Grand Prix by over 20 seconds over Lewis Hamilton and has won 14 of the 15 Grands Prix since Barcelona. Meanwhile, Perez began to feel a decline in his performance and instead of wondering if there was something wrong with the car, questions arose, especially in the media, that there was something wrong with Perez.

“[The 2023 Spanish Grand Prix] It was also the Grand Prix where Checo started to have problems with the car.” Horner said on Sunday.“Max kept winning so we didn't take it too seriously.”

Red Bull now have the answer – but how quickly they have it is another question and it may not be ready until October's United States Grand Prix in Austin. Speaking to media after Sunday's race, Marko said: With a stern warning Speaking about Red Bull's chances in the constructors' championship, one expert pointed to Austin as a potentially game-changing moment.

“Max couldn't even connect it. [in Baku]”The tyres broke and the brake temperatures rose. The car has potential but the set-up is still very sensitive.” said Marko: “There will be no improvement in Singapore. We will have to see how we get through that race, but we have to get a better result from Austin, otherwise the drivers' championship will be in jeopardy.”

Before then, Red Bull has one race left, this weekend's Singapore Grand Prix.

This is the only race Verstappen has not won since Barcelona last season.