IndyCar has had had a rough few years, as shakeups in engine suppliers, chassis designs and tragedy has dominated the open wheel race series’ headlines. In spite of all that, many have said this was IndyCar’s best season of racing ever. The man who oversaw all of that is Randy Bernard, who has stepped down on Sunday as IndyCar’s CEO, ending a three-year run. This development comes as the culmination of a coup by some team owners against the group that controls IndyCar, Hulman & Co. In addition to the race series, the group also owns Indianapolis Motor Speedway.

Though Bernard offered bonuses that attracted Indy 500 winner Dan Wheldon back to the series, it was Wheldon who perished in a crash at Las Vegas in 2011. The running of that race, as well as this year’s Vegas race and the season finale in California have all been criticized by some drivers for the high speeds reached on these tracks. Some drivers, like Mike Conway, even refused to race at this year’s season finale. While the Wheldon crash is considered a leading motivator in Bernard stepping down, team owners have also taken issue with the embattled series CEO’s lack of racing experience. Before running IndyCar, he was in charge of the championship bull-riding series.

A statement from IndyCar calls Bernhard’s departure a “mutual separation,” and many believe that given this year’s success, the series can weather this transition. Jeff Belskus, president and CEO of Hulman & Co will sit as interim IndyCar boss. Belskus tells the Associated Pressthat the series is looking for a long-term replacement.