to be the greatest Formula One driver of all time. In 2009, an Autosport survey taken by 217 Formula One drivers saw Prost voted as the fourth greatest Formula One driver of all time. In October 2020, The Economist ranked champion drivers by the relative importance of car quality to driver skill. According to this ranking, Prost is Formula One's third best driver of all time. In November 2020, Carteret Analytics used quantitative analysis methods to rank Formula One drivers. According to this ranking, Prost is Formula One's eighth best driver of all time. A 2022 mathematical analysis of all F1 drivers by f1-analysis.com put Prost as the 4th greatest driver of all time, and the second greatest once differences between different eras had been corrected for. In November 2022, Autosport ranked Prost as the statistical fourth best driver of all time. Rivalry with Ayrton Senna Prost's battles with Ayrton Senna were particularly notable. The rivalry originated in 1988, when Senna joined Prost at the McLaren team. The most notable event during the season between the two occurred during the Portuguese Grand Prix, where Senna tried to block Prost from taking the lead by forcing him to run close to the pit wall at around . Prost managed to edge Senna outwards, taking the lead as they went into the first corner, but remained angered by Senna's manoeuvre. The rivalry intensified after the 1989 San Marino Grand Prix, where the two drivers had an agreement that neither would get in each other's way to the first corner (cf. 1982 San Marino Grand Prix). At the start, Senna got away in the lead and Prost followed him through the first corner without getting in his way. Gerhard Berger's crash on lap four stopped the race. At the restart, Prost got away the better of the two but Senna forced his way past him at the first corner, breaking the pair's agreement at the start of the race, leaving Prost furious. Senna argued that it was the restart. Prost himself was angered by McLaren apparently favouring Senna because of Senna's better relationship with engine supplier Honda, so he announced in mid-season that he had signed to race for Ferrari the following season. Prost mentioned many times during 1989 that he believed his car was not as competitive as Senna's, and even that this was confirmed to him by the CEO of Honda