boston-red-sox-martin-perez-lrg-2

Seattle Mariners at Boston Red Sox Value Pick

By Darin Zank

Division leaders continue a four-game weekend series when the Red Sox meet the Mariners at Fenway Park Friday night. Boston went off this season playing against a wins over/under of 80.5 but leads the AL East in the early going. Seattle, meanwhile, is playing against an O/U of 72.5 but leads the AL West. The Mariners also took the opener of this series Thursday night in extra innings. How are we playing this game with our free MLB pick?

MLB Betting Odds

Friday’s baseball betting lines opened Boston and Martin Perez at around -140 over Seattle and Yusei Kikuchi, with an over/under of 9.5. Early betting action then dipped that line to -135.

Mariners-Red Sox MLB Betting Preview

Seattle grabbed the opener of this series Thursday night 7-3 in 10 innings. The Mariners actually trailed 2-0 and did not have a hit into the sixth inning, then tied the game with a couple walks and a double. Seattle later won the game with four runs in the tenth.

The Mariners cashed in as +160 underdogs on the betting odds Thursday night, and the game played over a total of nine runs thanks to Seattle’s 10th-inning outburst.

Earlier this week the Mariners split two games at home with the Dodgers, and going back a bit further Seattle is 6-2 over its last eight games.

At 12-7 overall the Mariners are tied with Oakland for first place in the AL West.

Boston split two games at home with Toronto earlier this week, and going back a bit further the Sox are only 3-5 over their last eight games. At 12-8 overall Boston leads the AL East by a game and a half over second-place Tampa Bay.

Friday’s Pitching Match-Up

Lefty Perez is 0/3 on quality starts this season. Last Sunday he got touched for four runs and seven hits through just 3 2/3 innings of a 5-1 Boston loss to the White Sox. And in his two starts previous to that he gave up five runs and nine hits through 10 innings. So on the season Perez has allowed nine runs on 16 hits and five walks through 13 2/3 innings.

And yet the Red Sox are 2-1 with Perez this year.

This will be Perez’ first action against Seattle since 2018, when as a Ranger he gave up eight ER over four starts, covering 18 2/3 innings. Texas won three of those four games.

Fellow southpaw Kikuchi, by our tough standards, is 1/3 on quality starts this season. Last Friday he gave up five runs and six hits through seven innings of a 6-5 Mariners win over Houston. And in his two starts previous to that he allowed five runs through 12 innings, with 16 strikeouts. So on the season Kikuchi has allowed 10 runs on 17 hits and six walks through 19 innings.

Seattle is 1-2 with Kikuchi this season.

In his only career start against Boston, back in 2019, Kikuchi allowed three runs – two earned – through six innings of a game the Mariners eventually lost 7-6.

Splits With the Sticks

Seattle is batting just .183 this season against left-handed pitching, with a .291 team OBP and a .331 team slugging percentage.

Boston is batting .271/.307/.449 vs. LH pitching this season.

The Bullpens

The Mariners bullpen owns a 2.62 ERA this season, third-best in the Majors, along with a 1.03 WHIP and a 2.10 K/BB ratio.

The Red Sox pen owns a 3.18 ERA, a 1.26 WHIP and a 2.25 K/BB ratio.

MLB Betting Trends

  • Favorites are 124-121 in MLB this season.
  • Favorites are 88-155 against the run line this season.

Totals Report

  • Overs are 10-8 in Mariners games this season.
  • Overs are 11-9 in Red Sox games this season.
  • Unders are 151-119 in MLB this season.

Mariners vs. Red Sox Prediction 4/23/21

We’re giving Kikuchi a short edge in this pitching match-up and while Boston owns an edge with the sticks Seattle gets the check-mark in the bullpen comparison. Plus the M’s are getting an underdog price. So we’re betting Seattle with our free MLB pick for Friday. 

Free Pick: Take the Mariners +125
Bovada

SOLID 50% BONUS - UP TO $250 FREE!

MLB Free Picks

Bet on Starting Pitcher Value With MLB Five-Inning Lines

Bet on Starting Pitcher Value With MLB Five-Inning Lines

Similar to betting the first half of an NFL football game, an MLB five-inning line covers the first half of action in a baseball game. Since baseball betting lines, in general, are heavily weighted on each team's starting pitcher, their impact on the game's outcome...

Betting MLB Dime Lines at Select Online Sportsbooks

Betting MLB Dime Lines at Select Online Sportsbooks

Baseball is back on the betting board at your favorite online sportsbook. One of the most popular ways to bet on the games is by using the posted money line odds. An MLB money line handicaps the straight-up result for a game by increasing the financial risk to bet on...

Betting MLB Win Totals

Betting MLB Win Totals

One of the most popular betting props ahead of any MLB regular seasons is on the odds for each team’s projected win total. Given that the schedule covers 162 games, there can be a rather wide margin of error in any projected total. Going through the list of each MLB...

The Statinator’s April 25, 2026 MLB Recap: -8.7 Units on a 2-5 Card

Betting the OVER/UNDER on MLB Props for Home Runs and Total Wins

With spring training underway for all 30 MLB teams, there is a renewed interest in betting the posted props for individual player performances in the regular season. Options like which slugger hits the most home runs and which ace has the most wins are fun and...

BEST SPORTSBOOK BONUSES

Stop wasting money! Start receiving at 30% Rebate at Betanysports

YES! There are still online sportsbooks where your credit card will work! You get a 50% bonus as well! –> Bovada

Deposit $100 to $1000 and get a MASSIVE 50% Sign-on bonus! MyBookie