Excerpt from my full game prediction on our website:

I really dig the value of a bet on the Diamondbacks ML at roughly +150 odds. Logan Webb hasn't been terrible, but he's put too many runners on base this season (17 in his last two starts combined). He isn't striking out a lot of batters, either (five or fewer Ks in all four starts). Arizona has plenty of offensive weapons and is averaging 5.7 runs per game. Given the Giants' struggles on offense, I don't expect Ryne Nelson to struggle much. San Francisco has scored three or fewer runs in eight of its last twelve games and is slashing .233/.307/.370/.677 vs. right-handed pitchers this season.

Webb may be the bigger name, but I believe Nelson will hold his own tomorrow. With early run support, he should last long enough to give his tired bullpen a rest. Besides, I'm not confident the Giants will have better luck against the D-Backs' pen. If anything, bettors should be wary of the home team's relief group (5.05 ERA).