Is Phil Mickelson Cheating?

First there was Tiger.

Now Phil Mickelson is the next golf superstar to be accused of cheating.

"Shady clubs" could be cited as common to both cases, but the accusation against Mickelson in truth concerns a very different kind of cheating.

PGA tour member and fellow American Scott McCarron has accused Mickelson of using an illegal golf club. 

"It's cheating, and I'm appalled Phil has put it in play," McCarron said in today's San Francisco Chronicle.

The club at issue is a wedge with square-grooves, which allows a player to spin the ball easier, including out of the rough, to make up for tee shots missing the fairway.

Square-grooves were banned starting with the 2010 PGA season, but there in an exemption for clubs built prior to 1990, as a result of a lawsuit by Ping. Otherwise, players must use clubs with V-shaped grooves.

Mickelson wasn't the only one using the old square-groove club.

"All those guys should be ashamed of themselves for doing that," McCarron said. Then he laid into Mickelson again, "As one of our premier players, Phil should be one of the guys who steps up and says this is wrong."

Later asked if he regretted the comment, McCarron did not back off his choice of words. "I still feel strongly about it," McCarron said. "Anyone using that wedge, I feel, is behind the rules, even though we have a rule that because of a lawsuit says it's OK."

Here was Phil's response to the accusation: "Don't put the blame on a player. Put the blame on the governing body. This whole groove thing has turned into a debacle. It's a terrible rule. To change something that has this kind of loophole is nuts," he said.

"But it's not up to me or any other player to interpret what the rule is or the spirit of the rule. I understand black and white. And I think myself or any other player is allowed to play those clubs because they're approved—end of story."

Mickelson added that he submitted wedges that met the new rules (V-shaped groove) yet were not approved for use by the USGA, while the old square Ping wedge he submitted was approved by the USGA.

What's interesting is if you look closer at the type of game played by the golfers making the accusations and the type of game played by those on the receiving end of them.

The biggest benefit of the club in question is to long-hitters who drive the ball far enough to leave themselves a wedge for their approach, but often miss the fairway. The wedge has much less benefit for shorter-drivers who are accurate off the tee.

Phil Mickelson finished 2009 ranked 13th in driving-distance, at over 300 yards. Meanwhile, he was 179th in driving-accuracy. This placed him 6th last, with barely 50% of fairways hit.

Scott McCarron finished the 2009 season ranked 3rd on the entire PGA tour in driving accuracy, yet was ranked 114th in driving distance.

Rocco Mediate, who backed up McCarron's stance, is currently 8th in driving accuracy.

John Daly was another of those using the "cheating" club.

McCarron also missed the cut today at the Farmers Insurance Open, taking place at the renowned Torrey Pines Golf Course. Mickelson, meanwhile, is currently tied for 10th, just four shots back of lesser-known leaders heading into the weekend.

McCarron has won three times on tour in his career. Mickelson has won three majors, and holds 37 PGA tournament victories.

Would McCarron be making the same claim if he hit the ball 300 yards, missed half of his fairways, yet had established himself as arguably the world's second-top player behind the now-absent Tiger Woods? Might he possibly be using the "cheating" club himself?

Is Mickelson at fault or fully justified in searching for and finding a loophole to counter a new rule put in that hurts his type of game at the expense of players with a style of game like McCarron?

One thing is for certain: it's hard to claim an unbiased perspective on the issue if your name is Phil Mickelson or Scott McCarron.