The Chicago White Sox host the Seattle Mariners on May 9, 2026. First pitch from Rate Field is scheduled for 7:10 p.m. EDT. The game will be broadcast on SEAM.
The Mariners are favored by -134 on the moneyline and by -1.5 on the run line. The White Sox are +114 on the moneyline and +1.5 on the run line. The total is set at 9.5 runs.
Find my MLB picks and Mariners vs White Sox prediction below, as well as probable pitchers, weather report, and more.
Mariners vs White Sox Prediction
- Mariners vs White Sox Pick: White Sox ML (+110 or Better) | White Sox F5 ML (+110 or Better)
My Mariners vs White Sox best bet is on Chicago to win both halves. Make sure to find the best odds by checking our live MLB odds page.
Mariners vs White Sox Odds
| Mariners Odds | ||
|---|---|---|
| Spread | Total | Moneyline |
-1.5 +118 | 9.5 -105o / -115u | -134 |
| White Sox Odds | ||
|---|---|---|
| Spread | Total | Moneyline |
+1.5 -142 | 9.5 -105o / -115u | +114 |
- Mariners vs White Sox moneyline: Mariners -134, White Sox +114
- Mariners vs White Sox over/under: 9.5 (-105o / -115u)
- Mariners vs White Sox spread: Mariners -1.5 (+118), White Sox +1.5 (-142)
Mariners vs White Sox Probable Pitchers
| Luis Castillo (RHP, SEA) | Stat | Anthony Kay (LHP, CHW) |
|---|---|---|
| 0-3 | W-L | 1-1 |
| 0.4 | fWAR (FanGraphs) | -0.2 |
| 6.29 / 5.86 | ERA / xERA | 5.70 / 7.62 |
| 4.24 / 4.63 | FIP / xFIP | 6.40 / 5.65 |
| 11.2% | K-BB% | 3.5% |
| 33.0% | GB% | 39.2% |
| .367 | BABIP | .299 |
| 98 | Stuff+ | 103 |
| 111 | Location+ | 101 |
Mariners vs White Sox MLB Betting Preview
To be clear from the start, I’m not trying to convince you Anthony Kay has been anybody’s idea of a good pitcher in his return to the league this year (5.28 SIERA, 7.60 xERA). In fact, he’s been even worse than his opponent, Luis Castillo (4.44, 5.84).
However, what do we always look for in Luis Castillo starts?
Is he at home? No
Is he facing a predominantly left-handed lineup? Seven projected.
LHBs vs Luis Castillo on the road:
- Career: .350 wOBA
- 2026: .364 wOBA
- 2025: .405 wOBA
The difference is that RHBs are above a .400 wOBA against Castillo too away from Seattle this year.
Castillo was averaging 97.1 mph on his fastball as recently as 2022, but is now down to 94.9 mph.
Mariners vs White Sox Pick, Betting Analysis
Here are some additional comparisons:
- Team Home/Road wRC+ 2026: White Sox 86/Mariners 81
- Team vs RHP 2026: White Sox 92/Mariners 82
- Projected LU vs RHP since 2025: White Sox 122/Mariners 111
- Projected LU wRC+ L30 days overall: White Sox 128/Mariners 112
There are certainly some sample size issues in the above numbers, but there is some smoke.
The projected Chicago (AL) defense also has a 17 Fielding Run Value edge over Seattle, and that's not a sample size blip.
I’m not sure the White Sox should even be dogs here.
I'm splitting a unit between F5 and the full game.
Pick: White Sox ML (+110 or Better) | White Sox F5 ML (+110 or Better)
