Shane Lowry and J.B. Holmes share the lead through 36 holes of the 148th Open Championship, but neither are the odds-on favorite to capture the claret jug. In fact, according Westgate Las Vegas SuperBook, neither is the second favorite or even the third. 

Lowry is fourth on the list, at 8/1. Holmes is further down, at 16/1. The favorite, as many might expect, is Brooks Koepka, who is going for his fifth major victory in his last 10 starts.

Here's a look at the odds entering the third round at Royal Portrush.

Brooks Koepka: 5/1

Tommy Fleetwood: 11/2

Justin Rose: 7/1

Shane Lowry: 8/1

Jon Rahm: 14/1

Jordan Spieth: 14/1

Lee Westwood: 14/1

J.B. Holmes: 16/1

Dustin Johnson: 20/1

Cameron Smith: 30/1

Matt Kuchar: 30/1

Xander Schauffele: 30/1

Henrik Stenson: 40/1

Justin Harding: 40/1

Rickie Fowler: 40/1

Tony Finau: 40/1

Patrick Reed: 50/1