Sports gambling is a global phenomenon—but I’m guessing you can’t name the world’s most-manipulated sport. Soccer? Basketball? Try tennis. This sprawling, two-part feature from Kevin Sieff unpacks the story of Grigor Sargsyan, the man behind the biggest match-fixing scandal in the sport’s history. Known as “The Maestro,” Sargsyan went from a poor neighborhood in Brussels to a puppetmaster pulling the strings on thousands of low-level tennis matches across world. You won’t be able to tear yourself away.

They walked outside. Sargsyan made his offer. He would pay the player to lose the second set of the match 6-0. The man accepted instantly, Sargsyan recalls.

The odds on the match were 11 to 1. The player tanked, just as he said he would, missing even easy returns, double-faulting, performatively slapping balls into the net. Sargsyan walked away with nearly $4,000. He paid the player, whom he would not identify, about $600.

“It was an incredible feeling,” he said.

If there was something about the rush of competition that had almost broken him in his chess career, filling him with an overwhelming sense of losing control, fixing tennis matches felt like a renewed source of power.