It's safe to say things didn't go quite as expected Friday at the storied Merion Golf Club, which in and of itself might be the most impressive surprise of the 2013 U.S. Open to date.
Once considered too short to host the U.S. Open, Merion tested the mettle of every golfer that challenged it during the second round and took many of them out to the woodshed. Stars like Phil Mickelson, Tiger Woods, Graeme McDowell and Lee Westwood struggled at times, or over the course of the entire round.
Pleasant surprises also emerged, including Billy Horschel and Steve Stricker, who somewhat unexpectedly sit high on the leaderboard as we turn to what should be an exciting weekend.
Here are the biggest winners and losers on a day that was so unpredictable at Merion that one player managed to make both lists.