The Seattle Mariners host the Boston Red Sox on June 20, 2026. First pitch from T-Mobile Park is scheduled for 10:10 p.m. EDT. The game will be broadcast on NESN.
The Mariners are favored by -125 on the moneyline and by -1.5 on the run line. The Red Sox are +105 on the moneyline and +1.5 on the run line. The total is set at 7.5 runs.
Find my MLB picks and Red Sox vs Mariners prediction below, as well as probable pitchers, weather report, and more.
Red Sox vs Mariners Prediction
- Red Sox vs Mariners Pick: Connelly Early Over 5.5 Strikeouts (-140, bet to -200; or 6.5 to -120)
My Red Sox vs Mariners best bet is on Connely Early K's prop. Make sure to find the best odds by checking our live MLB odds page.
Red Sox vs Mariners Odds
| Red Sox Odds | ||
|---|---|---|
| Spread | Total | Moneyline |
+1.5 -200 | 7.5 100o / -120u | +105 |
| Mariners Odds | ||
|---|---|---|
| Spread | Total | Moneyline |
-1.5 +165 | 7.5 100o / -120u | -125 |
- Red Sox vs Mariners moneyline: Red Sox +105, Mariners -125
- Red Sox vs Mariners over/under: 7.5 (+100o / -120u)
- Red Sox vs Mariners spread: Mariners -1.5 (+165), Red Sox +1.5 (-200)
Red Sox vs Mariners Probable Pitchers
| LHP Connelly Early (BOS) | Stat | RHP Emerson Hancock (SEA) |
|---|---|---|
| 5-5 | W-L | 5-3 |
| 0.3 | fWAR (FanGraphs) | 1.2 |
| 3.81/4.55 | ERA / xERA | 3.28/4.48 |
| 4.99/4.34 | FIP / xFIP | 3.80/3.66 |
| 13.1% | K-BB% | 18.5% |
| 40.7% | GB% | 41.5% |
| .277 | BABIP | .257 |
| 101 | Stuff+ | 101 |
| 98 | Location+ | 107 |
Red Sox vs Mariners MLB Betting Preview, Pick
Here’s something I can’t believe it’s taken me this long to realize.
Let me restate that.
I can’t believe it’s taken me this long to quantify.
The Mariners are generally in a situation, being so predominantly left-handed, that they often play several LHBs against same-handed pitching.
We also have a park that boosts strikeouts some 15-20%, depending on the handedness of the batter (Statcast 3 year rolling park factors).
This puts us in a situation where LHPs with solid strikeout rates against LHBs are in an excellent spot to exceed underpriced strikeout props, especially if they’re likely to get some umpiring help.
Connelly Early has struck out 31.1% of LHBs in 18 career starts. Admittedly, fewer this year in 14 starts (23.5% of 81) than last year in four (59.1% of 22), but remaining above average.
The Mariners started four LHBs against Ranger Suarez on Friday and are projected to run out another four on Saturday. The expectation is for Early to face LHBs around 10 times.
Based on the number of left and right-handed batters Early might face, I project his park boost somewhere close to 19%.
Scheduled umpire Paul Clemons not only suppresses run scoring slightly, but has a top 10 K/9 among major league umpires, translating into a near 7% bump.
That’s potentially a huge boost for Early on Saturday night.
Pick: Connelly Early Over 5.5 Strikeouts (-140, bet to -200; or 6.5 to -120)
