SAN FRANCISCO — Tiger Woods tried his best to put a positive spin on things, even when there was nothing positive about his weekend.

Another opportunity lost. Another chance to win a major championship gone.

For two rounds, Woods seemed to be in command in the U.S. Open. Then came a weekend of frustration that ran his winless streak in major championships to four years and raised even more questions about his ability to win the titles he used to take for granted.

He came into the final round Sunday still contending he had a chance at Olympic Club. Then he got off to a bogey-bogey-double bogey start that took away any chance of him mounting a charge up the leaderboard.

“There's a lot of positives this week. Hit the ball really well,” Woods said. “Unfortunately, I just didn't have the speed of the greens until today.”

Woods made some birdies coming in, but by then it was too late. He finished with a 3-over 73 that left him six shots back of winner Webb Simpson in a tournament Woods seemed poised to win after two rounds.

Tied for the lead going into the weekend, his game fell apart with a series of poor drives, chunked shots and putts that didn't come close to the hole. He was 8-over-par for the weekend, even while insisting that he did everything mostly right.

“I hit the ball very well the first two days and, as I said yesterday, I was just a fraction off just a couple yards here and there and that's all it takes,” Woods said. “I had so many balls that landed in the fairway that went into the rough.”