The launch of the LIV Golf Invitational Series has unleashed a maelstrom in global professional golf unlike any during Phil Mickelson’s three decades playing on the PGA Tour.

On Monday, Mickelson ended his four-month sabbatical from the sport when he signed a lucrative deal with the Saudi Arabian-backed tour for a reported sum of around $200 million. Mickelson said he used the time off for a period of reflection, during which an unauthorized biography about the six-time major winner was published chronicling his lengthy history of heavy gambling – both on the course through high-stakes practice rounds and at the window through large wagers on the NFL.

With Mickelson as the face of the breakaway tour, several major U.S. sportsbooks have begun to accept wagers on this week’s LIV series debut taking place Thursday-Saturday at the Centurion Club in London.