They were as firm as I've seen all year. They watered the slopes in front of the green and I would try to hit the slopes and the ball would stop instead of releasing. I have to learn how the greens are reacting better.

It's just hard to fathom because I have played with him in Ryder Cups and Presidents Cups and seen him at his best. It's just hard for me to visualize him at anything but his best. I just can't understand what's going on.

I've learned a lot. But it's not like I could just cram that into a year and have it all down. It's taken me years of seeing what's worked well and what hasn't.

If we had kept those undulations and slopes, golfers wouldn't be able to keep it on the green now.

He's still very good, ... He's still better than good. But in comparison to last year, that's what I've seen since the end of last season.

I love competing against the best players. I have a huge challenge, and that's to win a U.S. Open and complete the Grand Slam. I enjoy that challenge. Every year it comes around, I get excited to try to conquer that opportunity. I love it.