One great hole could give you great confidence, and that's it. But one bad hole could destroy your chances of winning.
Welcome to the sport of golf.
Tiger Woods' chance of winning his first major of the year came crumbling down on the sixth hole after shooting a triple-bogey.
His day hasn't gone so well, but there are others to talk about too. Here is an update on some of the stars of the event.
Adam Scott (-9)
Adam Scott hasn't needed to be incredibly sharp on Sunday given his lead. He hasn't performed up to his consistent standards in the tournament, but he still holds a comfortable lead.
Scott is at two-over par on the day after eight holes. He is four shots ahead of Graeme McDowell.
Graeme McDowell (-5)
McDowell hasn't been able to build off of his three-under 67 Saturday. A couple of bogeys, and McDowell's chances to make a comeback look bleak.
With only the back nine remaining, McDowell needs to start taking some chances.
Tiger Woods (-4)
After his triple-bogey on the sixth hole, Woods has been average. He recorded a birdie right after his triple-bogey, but then he recorded a bogey on the ninth hole.
With eight holes to play, Woods is now five strokes behind the leader.
Brandt Snedeker (-4)
Snedeker was the star of the tournament after two rounds. Since then, however, he's been the talk of the tournament in a negative way. After a 73 Saturday, Snedeker is currently shooting a three-over par on the day.
After appearing to be in perfect position to win a major after two rounds, Snedeker can't wait until the tournament finishes.
Luke Donald (-2)
Another major goes by and the world's best player fails to win. Luke Donald failed to make a move on Saturday, shooting a one-over par.
Donald has played decently well on Sunday, shooting one-under par on what has been a tough course today. But with his inability to close on Saturday, his efforts will be for naught in the win column.