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The stakes are high for Sunday's final round of the PGA Championship at the Ocean Course on Kiawah Island, the year's last major as well as the final opportunity for golfers to qualify for the Ryder Cup.

The start of the fourth round was delayed due to rain that forced the conclusion of yesterday's round into this morning. But some brilliant performances from competitors atop the leaderboards have made the final round worth the wait.

The top of the leaderboard was dominated by the bogey-free Rory McIlroy, who won the tournament by eight strokes after a 5-under final round. There were several strong performances by golfers including Ian Poulter, who started white-hot, including a stretch with five straight birdies, but ultimately finished nine strokes back. English golfer David Lynn, who finished second, also finished strong with a 4-under 68 on Sunday.

However, there have been a number of disappointing performances through the weekend from golfers who failed to live up to expectations in the Championship.

Let's take a look at a few golfers who fared worse than predicted as we head towards the end of the PGA Championship.

Tiger Woods (-2)

Let's get one thing straight about Tiger Woods: he is still the best golfer in the world.

Any time he enters a tournament, Tiger's name is almost certain to be near the top of the leaderboard. Woods leads the FedEx point standings over Zach Johnson even though he has only played in 15 events. He has made the cut in every major this year and has three wins in 2012. By anyone else's standards, he has had a brilliant year.

Unfortunately for Tiger, the only standards applied to him are the impossibly lofty standards he set over the past decade or so, when he consistently golfed at a level we'll likely never see from any player again (Rory McIlroy's rise notwithstanding).

Though he's now 37 years old and battling several injuries, it's unlikely that Tiger is done winning majors. It does, however, seem like a long shot for him to break Jack Nicklaus' record of 18 major victories, something that seemed like a good bet not long ago.

To that end, the expectation for Tiger is to win championships, not simply remain competitive. It seems as if this pressure has been getting to him. According to the Elias Sports Bureau, heading into the PGA Championship, Tiger was the best on the Tour in the first two rounds of play in 2012 majors, and the worst among players who made the cut in the final two rounds.

The trend continued for Tiger at the PGA Championship.

He shot a 69 in the first round of the tournament, bringing him within a couple shots of the leaders on Day 1. He shot a decent 71 on Friday before scuffling again during the weekend, shooting a rough 74 and leaving plenty of opportunities out on the green with some rough putting. He finished the tournament off with a 72, dropping him into tenth place for the tournament. It was a solid finish for most, but not Tiger, who finishes a solid year without a win in a major tournament.

Phil Mickelson (+2)

Chalk it up to a young writer's tendency to err towards forgivingly-ambiguous euphemisms when I refer to World Hall of Fame golfer Phil Mickelson's recent play as inconsistent. A more accurate description of his performances of late would be bad, at least by his standards.

Mickelson missed the cut at the British Open and the Greenbrier Classic, came in 65th with a dreadful performance at the U.S. Open, and finished 4-over at the Bridgestone Invitational. Though he had some high points this year (including his one tournament win at Pebble Beach and his third-place finish at the Masters) he desperately needed a great performance in the PGA Championship in order to fully redeem a disappointing 2012 season.

He didn't get one.

Mickelson finished 3-over par with no single round under 71, which currently places him in a tie for 37th. He started his final round with a costly bogey on the first hole, which placed him eight strokes back of McIlroy to begin Sunday. He never recovered, finishing the round with a 74, worse than his any of his first three rounds at the tournament.

Adam Scott (-2)

Adam Scott has yet to recover from his collapse at the British Open just a few short weeks ago.

Scott played well in the PGA Championship, finishing Saturday in the hunt with a solid 213. Still, PGA fans waiting to see how he recovers from the collapse at Royal Lytham & St Anne's—where he was overtaken by Ernie Els in a historic four-stroke collapse in four holes. There wasn't much in the way of resolve in his final round at the PGA Championship, where he finished his final round 1-over par.

Scott, who has won dozens of tournaments but has yet to win a major to back up all the hype surrounding him, needs to prove his mettle in these pressure situations if he hopes to realize that potential and fulfill all the talk of his being a young prodigy in the golf world. Hopefully for fans of Scott, he'll win a major soon, so that all the pity associated with his collapse turns into pride in his finally realized potential.