It's a crowded U.S. Open leaderboard, with big names and some not so well known

That’s one giant traffic jam, with 13 players bunched at one under, even par or one over. Although that cluster includes Dustin Johnson, the world’s top-ranked player, and No. 3 Justin Rose, there are also a host of lesser-known competitors. Eight of the players in that logjam aren’t ranked in the top 50, and three of those haven’t cracked the top 170. It’s as much “who’s he?” as who’s who.