Phil Mickelson Jul 15, 2022; St. Andrews, SCT; Phil Mickelson tees off on the 15th hole during the second round of the 150th Open Championship golf tournament at St. Andrews Old Course. Mandatory Credit: Michael Madrid-USA TODAY Sports

It’s no secret to anyone who has followed Phil Mickelson that he is a prolific sports gambler, but it looks like his gambling habits are far more astounding than was ever previously reported.

In his new book, iconic sports gambler Billy Walters – widely considered the most successful sports gambler of all-time – detailed his relationship with Phil Mickelson and also revealed that Mickelson had a history of placing absolutely massive wagers and has wagered “a total of more than $1 billion” over the past three decades.

Here is an excerpt from Walters’ book detailing Mickelson’s absolutely insane gambling habits, via Golf Digest:

After my betting partnership with Phil ended in the spring of 2014, I learned a lot more about his sports gambling from two very reliable sources.

They said it was nothing for Phil to bet $20,000 a game on long-shot, five-team NBA parlays. Or wager $100,000 or $200,000 a game on football, basketball, and baseball. Based upon my detailed betting records and additional records provided by the sources, here is a snapshot of Phil’s gambling habit between 2010 and 2014:

• He bet $110,000 to win $100,000 a total of 1,115 times.

• On 858 occasions, he bet $220,000 to win $200,000. (The sum of those 1,973 gross wagers came to more than $311 million.)

• In 2011 alone, he made 3,154 bets—an average of nearly nine per day.

• On one day in 2011 (June 22), he made forty-three bets on major-league baseball games, resulting in $143,500 in losses.

• He made a staggering 7,065 wagers on football, basketball, and baseball.

Based on our relationship and what I’ve since learned from others, Phil’s gambling losses approached not $40 million as has been previously reported, but much closer to $100 million. In all, he wagered a total of more than $1 billion during the past three decades.

He also revealed that Mickelson tried to bet $400,000 on a Ryder Cup in which he was competing.

[Golf Digest]