Cubs vs. Diamondbacks Prediction and Odds for Sunday, May 15 (Stick With Profitable Under Trend)

After splitting the first two games of the series in a pair of close contests, the 18-16 Arizona Diamondbacks host the 12-20 Chicago Cubs today at 4:10 PM EST.

Humberto Castellanos will pitch for Arizona and he's been a mixed bag so far this year. He's capable of throwing 5.2 scoreless innings against the Marlins like he did two starts ago, but he's also prone to give up five runs in two innings as he did against the Cardinals in the start before that.

Chicago will counter with Justin Steele, who serves as a sort of long reliever to open a bullpen day. He has a 5.32 ERA in six starts but is averaging only 3.2 innings per outing.

Which inconsistent pitcher has the edge in this one? Can Arizona get revenge for last night's loss or will Chicago claim a series victory?

Here are the odds from WynnBET as we answer those questions and find a winner in this Cubs vs Diamondbacks matchup:

Cubs vs Diamondbacks Odds, Run Line and Total

Run Line:

• Cubs +1.5 (-190)
• Diamondbacks -1.5 (+155)

Moneyline:

• Cubs: +107
• Diamondbacks: -117

Total:

• 9.0 (Over -105/Under -115)

Cubs vs Diamondbacks Prediction and Pick

We've got a battle between two pitchers due for some positive regression. Humberto Catellanos has a 4.32 ERA but just a 3.44 FIP (Fielding Independent Pitching) while Justin Steele has a 5.32 ERA and 3.76 FIP. That means both starters have been a bit unlucky and have performed better than their box score statistics may suggest.

The Diamondbacks rank 23rd in OPS against left-handed pitchers and the Cubs are 29th in OPS in May, so neither lineup is particularly dangerous right now either. And both starters are among the league's best in preventing hard contact, with Castellanos ranking in the 92nd percentile in barrel percentage and Steele scoring in the 96th.

All season long, the under has been a money bet for Arizona home games. It's 16-4 in contests at Chase Field and a perfect 5-0 when the Diamondbacks are favorites. Meanwhile, it's 4-2 in Chicago's last six on the road.

I see no reason for things to change today. With both lineups struggling situationally and a pair of pitchers due for better luck, I'm backing the under to improve to 17-4 when Arizona is at home.

Pick: Under 9.0 (-105)

Follow all of Joe Summers' betting picks here.