The scoring average was higher than in the previous two times the venue hosted the Open.
This is an article from the June 24, 2013 issue
Only two holes at Merion played under par—the 1st and the 13th. The most difficult holes were the 5th and the 18th, par-4s that each played to a stroke average of 4.706. That's the highest average on the PGA Tour since the 6th hole at Royal Birkdale played to a 4.764 average at the 2008 British Open. And the birdie that Phil Mickelson made at the 18th on Friday was the last of the week at the closing hole. None of the 73 players who made the cut birdied the hole on Saturday or Sunday.