The leaders have yet to tee off on the final day of the 2012 U.S. Open on Sunday, but there's progress being made at the Olympic Club in San Francisco.
The biggest ground-gainer in the early going of Sunday's fourth round is K.J. Choi, who is 2-under through his first nine holes and has moved into a tie for 17th place at 5-over. While Choi still has plenty of work left to do, being under par through the spectacularly tricky first nine holes is a good indication that he's on top of his game today. Choi may be making a late move and is certainly someone to keep an eye on.