Water hazards.. Sand traps and the run off behind the greens. All things golfers of this caliber must know heading into a big event like the U.S. Senior Open.
Bernhard Langer has already won a major this season and played here in the 1988 PGA Championship - and he is meticulous in practice rounds.
"Obviously I can't remember anything for 26-years ago. It looks like a brand new golf course to me." said Langer. "I just trying to get an idea of what every green looks like and where to miss it and where not to miss it. And what the dangers are. That's why we have a yardage book and make notes. I don't play without a yardage book. No one does anymore. It's a miracle to me how the old guys used to play with just eye sight. Especially on hilly courses they would just eye ball it and go looks like a 5-iron, but I couldn't do that."
Bob Tway is one of four guys playing here this week who call Oak Tree National their home. Despite the years of course knowledge, he says it's good to get out and practice - because the Oak Tree course they usually see won't be the one they'll play this week.
"Most of the time I'm trying to get to know the golf course." said Tway. "This is different because I pretty much already know the golf course. You're putting from different places because the speed of the greens are a little faster than what we normally play so you're getting accustom to that. And actually the balls are rolling a little farther on the fairways than normal because the fairways are cut lower. So, there are a few things that are different."
Practice rounds continue on Tuesday, with the first round getting underway on Thursday morning.