Former NBA referee Tim Donaghy conspired to fix NBA games between 2006 and 2007, “unwittingly” helping gamblers win an estimated hundreds of millions of dollars, according to a blockbuster Tuesday report from ESPN. During the 2006-2007 season, Donaghy—who pleaded guilty in 2007 to conspiracy to commit wire fraud and conspiracy to transmit gambling information—called unnecessary fouls in order to shift the outcome of NBA games and help his picks win, the outlet reports. He privately admitted to fixing games on four separate occasions, sources told ESPN. To prove that Donaghy made illegitimate calls, ESPN conducted two different statistical analyses. The first, based on fluctuations in betting prices, showed that he made calls that favored his picks during 23 out of 30 competitive games—and that the chances that an unbiased referee would make the same calls was 6,155-to-1. The second, which was based purely on his foul calls, found that there was a 4.1 percent chance that an unbiased referee would have made the same calls. “There were lots of whistles in the game, by him, that did not fit the game,” said the NBA’s former director of officiating.