The manoeuvre first appeared in 2019, when Simon Pagenaud used the tactic to keep his rivals at bay on the way to victory for Team Penske.
In recent years, it has become more prevalent – with some drivers swerving wildly off Turn 4 and into the pitlane entrance to deter those following from using their slipstream. Josef Newgarden used the move to help him to stay ahead of Marcus Ericsson on the final lap on Sunday.
The cars then swerve to rejoin the racetrack just ahead of the pitwall attenuator, which is viewed as one of the most dangerous areas on the legendary 2.5-mile oval.
The moves are not against IndyCar rules, as the leading car is the instigator of the change of direction rather than making a reactionary blocking move, and there are no track limits rules at IMS.
One driver, who did not wish to be named, told Autosport: “Going down into the pitlane… You know, with the leaders, everyone has a clear view, it's fine.
“But imagine a bit further back with cars two wide and more, and someone ends up hitting that attenuator. I think that's when things start getting a bit unprofessional in a certain way.”
Sunday’s race winner Newgarden admitted after the race that he doesn’t “love” doing the move but was adamant that it is a legal and necessary under the current rules.
Source: Autosport