Red Sox vs. Mariners odds, line, start time, picks, best bets for June 18 American League matchup from proven model

The Boston Red Sox battle the Seattle Mariners in a key American League matchup on Wednesday afternoon. The Red Sox (38-37), who have won six of seven, are 16-20 on the road this season. The Mariners (37-35), who have won four of five, are 20-18 on their home field in 2025.

First pitch from T-Mobile Park in Seattle is set for 4:10 p.m. ET. The Red Sox have won five of the past nine meetings with the Mariners. Boston is a -120 favorite on the money line (risk $120 to win $100) in the latest Red Sox vs. Mariners odds from DraftKings Sportsbook, while the total number of runs Vegas thinks will be scored, or the over-under, is 6.5 in the latest MLB odds. 

Before you make any Red Sox vs. Mariners picks or MLB predictions, you need to see what the SportsLine Projection Model has to say.

The SportsLine Projection Model simulates every MLB game 10,000 times. It enters Week 13 of the 2025 MLB season on a 37-30 run on top-rated MLB sides picks. It has excelled making home run prop picks, returning more than 35 units of profit over the past two months. Anybody following could have seen strong returns!

The model has simulated Red Sox vs. Mariners 10,000 times and the results are in. We can tell you the model is going Over on the run total, and it also says one side of the money line has all the value!

Who wins Red Sox vs. Mariners, and which side of the money line has all the value? ... Join SportsLine right now to find out which side of the money line you should be all over, all from the model on a 37-30 roll on top-rated MLB picks!