World No. 1 Rory McIlroy struggles to figure out greens, shoots 72 in 1st round of US Open

Rory McIlroy, of Northern Ireland, stands on the fairway on the 16th hole during the first round of the U.S. Open golf tournament at Chambers Bay on Thursday, June 18, 2015 in University Place, Wash. (AP Photo/Charlie Riedel) (The Associated Press)

Rory McIlroy, of Northern Ireland, watches his tee shot on the 13th hole during the first round of the U.S. Open golf tournament at Chambers Bay on Thursday, June 18, 2015 in University Place, Wash. (AP Photo/Charlie Riedel) (The Associated Press)

UNIVERSITY PLACE, Wash. – Count Rory McIlroy among those who failed to figure out the tricky greens of Chambers Bay on the first day of the U.S. Open.

The No. 1 player in the world shot a 2 over 72 in the first round on Thursday. McIlroy believed from tee to green he was striking the ball to where he should have been.

But it was on the greens where McIlroy could not figure out the bumps and rolls of Chambers Bay.

McIlroy wasn't exceptionally pleased with the condition of the putting surfaces that are all fine fescue grass, the same as the fairways at the course outside Seattle.

He said "they're not the best I've ever putted on," but put the blame on himself saying he needs to find a rhythm to his putting stroke the next few days.