The Arizona Diamondbacks host the San Francisco Giants on May 18, 2026. First pitch from Chase Field is scheduled for 9:40 p.m. EDT. The game will be broadcast on ARID.
The Diamondbacks are favored by -139 on the moneyline and by -1.5 on the run line. The Giants are +115 on the moneyline and +1.5 on the run line. The total is set at 9 runs.
Find my MLB picks and Giants vs Diamondbacks prediction below, as well as probable pitchers, weather report, and more.
Giants vs Diamondbacks Prediction
- Giants vs Diamondbacks Pick: Over 9 (-115, FanDuel)
My Giants vs Diamondbacks best bet is over 9 total runs. Make sure to find the best odds by checking our live MLB odds page.
Giants vs Diamondbacks Odds
| Giants Odds | ||
|---|---|---|
| Spread | Total | Moneyline |
+1.5 +145 | 9 -115o / -105u | +115 |
| Diamondbacks Odds | ||
|---|---|---|
| Spread | Total | Moneyline |
-1.5 -175 | 9 -115o / -105u | -139 |
- Giants vs Diamondbacks moneyline: Giants +115, Diamondbacks -139
- Giants vs Diamondbacks over/under: 9 (-115o / -105u)
- Giants vs Diamondbacks spread: Diamondbacks -1.5 (+145 ), Giants +1.5 (-175)
Giants vs Diamondbacks Probable Pitchers
| Robbie Ray | Stat | Zac Gallen |
|---|---|---|
| 20-27 | W-L | 22-23 |
| 0 | fWAR (FanGraphs) | 0.1 |
| 3.04 / 4.58 | ERA / xERA | 5.02 / 5.33 |
| 4.92 / 4.30 | FIP / xFIP | 4.68 / 4.50 |
| 14.3 | K-BB% | 7.8 |
| 27.3 | GB% | 49.7 |
| .234 | BABIP | .317 |
| 101 | Stuff+ | 88 |
| 95 | Location+ | 108 |
Giants vs Diamondbacks MLB Betting Preview
The dome is expected to be open, and the wind will be blowing out with warm temperatures in Arizona. Winds could reach around 12 mph, and temperatures should sit in the 80s. It’s not going to be near 100 degrees like it can get on some days at Chase Field, but it’s cool enough to keep the roof open and still warm enough to positively impact the run-scoring environment.
Zac Gallen has been absolutely miserable this season. He owns just an 8% strikeout-minus-walk rate. My model kept trying to back him, but I’ve had to downgrade him closer to where he actually is right now because I think the multi-year decline we’ve seen in his metrics is supported by declining stuff and other concerning indicators.
At the moment, Gallen grades out closer to SP23 territory for me after previously profiling more in that SP1/SP2 range.
As for Robbie Ray, I also project him as more of a below-average starter right now. Even though his strikeout-minus-walk rate is still better than league average, he gives up a lot of hard contact. He’s allowing 1.8 homers per nine innings with a 12% barrel rate.
You can hide some of that in San Francisco. You cannot hide it at Chase Field.
Giants vs. Diamondbacks is an over for me. I make the total 9.6 and would bet over 9 up to -115.
Pick: Over 9 (-115, FanDuel)
