I have the over as well. Here's why:
Homer Bailey, despite what some people want to believe, is one of the most medicore pitchers out there, despite his previous high potential from years ago. Has he displayed shutdown stuff on occasion? Absolutely, he's had some truly magnificent outings. But more times than not, he comes off as hittable, and I feel this will be one of those starts. The big thing for us over bettors is that his split stats indicate he's much worse at home (5.93 ERA, 1.63 WHIP) than on the road (2.93 ERA, 1.08 WHIP), which isn't much of a surprise when you mostly reside at a hitter's haven like Great American Ballpark.
As for Jake Westbrook, talk about someone who is completely overachieving. Westbrook has always had the reputation of simply being a nice pitcher to have in the middle of the rotation, and that's justified. He's contributed some gutsy starts and solid strings of pitching, with this year being no exception. But so many times, there have been guys, veterans included, who have completely outpitched their talent in the beginning of the year, only to fall of the wagon and see their numbers decline towards their more normal production. I believe Westbrook will be another victim to that trend, much like I predicted for Jason Hammel (Very similar pitchers experiencing more so unusual success in the first half). I was right about Hammel in his first second half start (And now he's injured, ironically), and I think the same fate lies ahead for Westbrook, beginning tonight in this hitter's park. The over is a solid bet, although not a huge one, as the possibility of 5-3 is there, but for the most part, the signs point to an over.