On a day that saw plenty of red on the leader board – 39 rounds under par to be exact – there was still a significant advantage to teeing off in the morning on Thursday at the U.S. Open. The 78 players in the early wave had a stroke average of 72.05, compared to 73.35 in the afternoon – a difference of 1.30 strokes. While leader Justin Rose’s 6-under 65 came late in the day, 36 of the 57 rounds of par or better were shot in the morning, despite winds that actually decreased as the day wore on. In fact, players in the morning wave hit 2+ more greens in regulation on average than the afternoon wave, 11.9 to 9.8. On Friday morning, Rose will try to extend his lead, while two-time defending champion Brooks Koepka (69) and three-time U.S. Open winner Tiger Woods (70) will look to cut into the deficit. Other past champions including Jordan Spieth (72), Jim Furyk (73) and Webb Simpson (74) will need a good round to survive until the weekend.