Phil Mickelson and Tiger Woods are considered two of the greatest golfers in the sport's history. There are several similarities between the two golfers, one of which is Butch Harmon. The swing coach was originally Woods' coach and was later hired by Mickelson.
Harmon is one of the most respected swing coaches, best recognized for his time with Tiger Woods from 1993-2002. Woods enjoyed remarkable success under his leadership, and they parted ways on good terms in August 2002. Later in 2007, Mickelson hired Harmon to help him fix his swing.
In a 2009 interview with Golf Digest, Mickelson explained how he intended to hit more of his shots on the fairways. He summarized his progress with him at the time by saying:
"I don't believe you've seen the full benefits of my working with Butch yet. The numbers don't indicate the progress I feel, but I feel it happening. My misses are smaller; I'm closer to hitting more fairways."
He continued:
"My club isn't as far past parallel as it used to be, for one. My leg action is more solid and more consistent. Whenever I hit a bad shot, it's evident in the legs. Which doesn't mean if my legs are fixed that I'll hit a good shot."
Under Harmon, Phil Mickelson won two of his six major tournaments. The wins were at the 2010 Masters and the 2013 Open Championship.
Phil Mickelson once described Tiger Woods as an underestimated smack talker

Phil Mickelson and Tiger Woods faced off in a one-on-one event known as The Match: Tiger VS Phil. It occurred at the Shadow Creek Golf Course in North Las Vegas. The event was heavily hyped among fans, and CNN organized an interview with both golfers to provide additional coverage.
Mickelson spoke about Woods' smack-talking. The six-time major winner claimed that Woods used a very low voice when smack-talking so that it only reached the other golfers and no one else.
"You know, Tiger is an underrated smack talker, okay? He doesn't get the credit for his smack talk because he does it so understated, and he does it under his breath so nobody else can hear other than you. He does a great job with that, but this match he's going to be miked, and I think that fun side of him, that funny side of him, is going to come out," Mickelson said [0:23 onwards]
Phil Mickelson ultimately won the inaugural edition of The Match, and has since taken part in a number of editions of the event.