• The Mariners are -130 favorites vs the Red Sox
• Red Sox vs Mariners Over / Under today: 7.5 Runs
• Red Sox / Mariners TV Channel: NESN | MRTV

The Boston Red Sox (+105) visit T-Mobile Park to take on the Seattle Mariners (-130) on June 20, 2026. First pitch is scheduled for 10:10 pm in Seattle, WA.

This season, the Red Sox are 30-43 against the spread (ATS), while the Mariners are 30-47 ATS.

Red Sox vs Mariners Starting Pitchers Today:

• Red Sox starting pitcher: Connelly Early 5-5, 3.79 ERA
• Mariners starting pitcher: Emerson Hancock 5-3, 3.29 ERA

Red Sox vs. Mariners Odds, Run Line, Over/Under & Moneyline

Red Sox vs Mariners Prediction for Today’s Game

Based on recent trends the model predicts the Mariners will win Saturday‘s MLB game with 54.6% confidence, factoring in game simulations, recent player performances, starting pitchers and injuries.

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We’ve highlighted some favorite MLB player prop bets for Red Sox players for Saturday‘s game, looking at profitable historical betting trends:

Best Red Sox Player Prop Bets Today:

• Jarren Duran has hit the Home Runs Over in 3 of his last 10 away games (+12.30 Units / 123% ROI)
• Ceddanne Rafaela has hit the Total Bases Over in 16 of his last 25 games (+11.65 Units / 44% ROI)
• Marcelo Mayer has hit the Hits Over in 16 of his last 20 away games (+9.95 Units / 32% ROI)
• Marcelo Mayer has hit the Singles Over in 13 of his last 20 away games (+8.95 Units / 44% ROI)
• Jarren Duran has hit the Hits Runs and RBIs Over in 8 of his last 10 away games (+5.90 Units / 52% ROI)

And here are some favorite MLB player prop bets for Mariners players for Saturday‘s game, looking at profitable historical betting trends:

Best Mariners Player Prop Best Bets Today:

• Cal Raleigh has hit the Total Bases Under in 14 of his last 15 games (+12.90 Units / 58% ROI)
• Cal Raleigh has hit the Hits Under in 12 of his last 15 games (+12.85 Units / 86% ROI)
• Julio Rodriguez has hit the Home Runs Over in 4 of his last 9 games at home (+11.80 Units / 131% ROI)
• Cal Raleigh has hit the Hits Runs and RBIs Under in 13 of his last 15 games (+10.80 Units / 60% ROI)
• Cal Raleigh has hit the Runs Under in 13 of his last 15 games (+10.20 Units / 53% ROI)

Red Sox Best Bets Today:

• The Boston Red Sox have hit the 1st Five Innings (F5) Team Total Under in 22 of their last 35 games (+7.45 Units / 18% ROI)
• The Boston Red Sox have hit the Team Total Under in 30 of their last 50 games (+7.25 Units / 12% ROI)
• The Boston Red Sox have covered the Run Line in 14 of their last 23 away games (+6.75 Units / 20% ROI)
• The Boston Red Sox have hit the Moneyline in 14 of their last 23 away games (+5.45 Units / 22% ROI)
• The Boston Red Sox have hit the Game Total Over in 20 of their last 35 away games (+4.65 Units / 12% ROI)

Mariners Best Bets Today:

• The Seattle Mariners have hit the 1st Five Innings (F5) Team Total Under in 14 of their last 20 games at home (+7.80 Units / 32% ROI)
• The Seattle Mariners have hit the Team Total Under in 14 of their last 21 games at home (+7.50 Units / 34% ROI)
• The Seattle Mariners have hit the Game Total Over in 11 of their last 16 games (+6.85 Units / 39% ROI)
• The Seattle Mariners have hit the Moneyline in 8 of their last 11 games at home (+4.15 Units / 27% ROI)
• The Seattle Mariners have covered the 1st Five Innings (F5) Run Line in 22 of their last 40 games (+3.30 Units / 8% ROI)

Red Sox Against the Spread (ATS) Record

Against the spread this season, the Red Sox are 30-41 against the Run Line (-11.85 Units / -12.87% ROI).

• 30-43 when betting on the Moneyline for -21.85 Units / -24.54% ROI
• 33-37 when betting on the total runs Over for -7.85 Units / -9.77% ROI
• 37-33 when betting on the total runs Under for +0.45 Units / 0.56% ROI

Mariners Against the Spread (ATS) Record

Against the spread this season, the Mariners are 30-47 against the Run Line (-8.85 Units / -10.95% ROI).

• 39-38 when betting on the Moneyline for -10.9 Units / -10.39% ROI
• 38-36 when betting on the total runs Over for -1.3 Units / -1.53% ROI
• 36-38 when betting on the total runs Under for -5.6 Units / -6.61% ROI

Red Sox Keys to the Game vs. the Mariners

The Red Sox are just 2-23 (.080) when allowing 5 or more runs this season — lowest in MLB; League Avg: .207.

The Red Sox are just 1-37 (.026) when trailing entering the 8th inning this season — 2nd lowest in MLB; League Avg: .103.

The Red Sox are just 1-6 (.143) when tied entering the 8th inning this season — 2nd lowest in MLB; League Avg: .500.

The Red Sox are just 0-39 (.000) when trailing entering the 9th inning this season — tied for lowest in MLB; League Avg: .055.

Mariners Keys to the Game vs. the Red Sox

The Mariners are just 6-18 (.250) vs bottom 10 scoring offenses this season Today, they face the Red Sox (29th in runs scored).

The Mariners are just 5-14 (.263) vs the top 10 runs allowed teams this season Today, they face Red Sox (eighth in runs allowed).

The Mariners are 45-37 (.549) vs the top 10 runs allowed teams since the 2025 season Today, they face Red Sox (eighth in runs allowed).

The Mariners are 26-15 (.634) when tied entering the 7th inning since the 2025 season — 2nd best in MLB; League Avg: .500.

Red Sox Hitting Stats & Trends

Red Sox hitters are slugging just .490 in non-two strike counts this season — lowest in MLB.

Red Sox hitters have an OPS of just .682 (2,082 PA’s) against RHP this season — 5th lowest in MLB.

The Red Sox are just 9-20 (.310) against the run line (-31.7% ROI) after a win this season — 2nd lowest in MLB; League Avg: .492.

Red Sox hitters have an OBP of just .307 (1,204 PA’s) with runners on base this season — 2nd lowest in MLB.

Mariners Hitting Stats & Trends

The Mariners are batting just .211 against LHP this season — lowest in MLB.

Mariners hitters have an OPS of just .625 (818 PA’s) against LHP this season — lowest in MLB.

Mariners hitters have an OBP of just .292 (818 PA’s) against LHP this season — 2nd lowest in MLB.

Mariners hitters are slugging just .332 against LHP this season — lowest in MLB.

Red Sox Pitching Stats & Trends

Red Sox pitchers have walked 6% of batters when facing the leadoff batter in the inning this season — 3rd best in MLB.

The Red Sox have allowed 0.93 runs per game (68/73) in late innings this season — 2nd best in MLB.

Red Sox pitchers have induced opposing hitters to ground into just 36 double plays in 501 opportunities (7%) this season — 2nd lowest in MLB.

Red Sox pitchers have a strikeout rate of 28% in close and late situations this season — 2nd best in MLB.

Mariners Pitching Stats & Trends

Mariners pitchers have a first-pitch strike rate of 67% this season — highest in MLB.

Mariners pitchers have walked 6% of batters when facing the leadoff batter in the inning this season — best in MLB.

Mariners pitchers have walked 7% of batters this season — best in MLB.

Mariners pitchers have thrown at least two strikes in their first three pitches to 69% of opposing batters this season — highest in MLB.

More MLB Reading:

• Home Run Predictions Today
• Best NRFI Bets Today
• Strikeout Props Today
• MLB Starting Pitchers Today

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