Boston Red Sox vs Seattle Mariners Prediction, Odds and Picks for Monday, 06/16/25

The Boston Red Sox have won 5 straight, while the Seattle Mariners are fresh off a sweep over Cleveland, and we have an interesting pitching matchup set for this series opener. Logan Gilbert (2.37 ERA, 0.79 WHIP) makes his first start in over a month coming back from a strained right elbow, while Boston is sending out the wildly inconsistent Lucas Giolito (5.45 ERA, 1.54 WHIP). Giolito has given up 1 earned run or less in 4 of his last 7 starts, although the other 3 he gave up 6+ earned runs each time. He falls in the fourth percentile in xERA and 2nd percentile in xBA and faces a Mariners lineup that is top-6 in wRC+ against right-handed pitching.

Looking at each pitcher’s baseball savant page, the difference couldn’t be more drastic. Gilbert falls in the 90th percentile or better in xERA, xBA, whiff %, strikeout rate, walk rate, barrel % and extension. It’s understandable that Gilbert commands such a heavy price on the money line in this matchup, and because of that I believe the value lies in the run line. I’ll take Seattle to cover -1.5 at home.

Red Sox vs Mariners prediction: Seattle -1.5 (+120) available at time of publishing. Playable at that number to +100.

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