Round 1 of the U.S. Open is almost done — blame a 90-minute marine layer delay for pushing the end of the round into Friday morning — but sports books already know enough to adjust the lines for tournament favorites, sometimes severely. All lines courtesy BetMGM.
Jon Rahm finished his round at -2, good enough to nearly halve his odds of winning, from +900 pre-tournament to +550 (bet $100 to win $550) now. Right behind him, vaulting multiple pre-tournament contenders, sits Louis Oosthuizen at +750. Co-leader Oosthuizen has finished in second at every major, and solo third at the U.S. Open last year; could this be the year he gets it done?
If it's a major, Brooks Koepka must be in the hunt, and that means his odds have also dropped to +750 from a pre-tournament +1600 after a first-round two-under 69. Xander Schauffele, who also shot 69, has seen his odds fall from +1800 to +1000, the variances likely due to Koepka's experience closing the deal.
Also seeing nice bumps: Rory McIlroy (+1400) and Masters champion Hideki Matsuyama (+1600). Co-leader Russell Henley isn't getting a whole lot of love at +3300, but another day at or near the lead will change that.
But what goes down can also go up, and odds of several players increased significantly after Round 1 struggles. Jordan Spieth, for instance, was a 20-1 play before the tournament, and now is at 200-1 thanks to a six-over day that's already put him 10 strokes off the lead. Collin Morikawa, +2200 to enter the tournament, is now +10000 after a rough +4 day. And sentimental favorite Phil Mickelson, already at 55-1 coming into his latest attempt at a career Grand Slam, is now at 250-1 thanks to a +4 morning.
Round 1 wraps up early Friday morning, and we'll see all these lines slip and slide by the time the cut arrives Friday afternoon.
Jay Busbee is a writer for Yahoo Sports. Follow him on Twitter at @jaybusbee or contact him at firstname.lastname@example.org.
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