The Colorado Rockies are riding a six-game winning streak, including back-to-back wins here at Chase Field. They won Tuesday's contest 4-2, and I predict another low-scoring contest tonight.

German Marquez (10-6, 4.27 ERA) will take the ball for Colorado. The 22 year old right-hander has allowed eight runs (six earned) in 10 innings through his last two starts, but under is still 9-1 in his last 10 starts overall. He has held Arizona to 13 runs in five meetings covering 29 2/3 innings in five starts on the season, each game going under the total.

The D'Backs turn to Patrick Corbin (13-12 , 4.16 ERA) who was charged with eight runs on 11 hits and three walks through 4 1/3 frames of a 10-6 loss to San Diego his last time out. He had however been excellent during a five-game winning streak prior to that, allowing just a total of two earned runs in 35 2/3 innings.

Under is 4-1 in Corbin's last five starts against the Rockies.

My free pick is on the Under.