The Seattle Mariners visit the Washington Nationals on Saturday afternoon, and the betting market reads this one as a near coin flip. Both teams sit close to .500, yet they arrive in very different moods. Seattle leads the AL West and wants to wrap up a winning road trip. Washington, meanwhile, is fighting to end a home slide. The moneyline is priced as a pick'em, so the value lives in the matchup details. Our headline lean sides with the home club at an even number. Below, we break down the run line, the moneyline, and the total before settling on our picks.
Last Updated: Saturday, June 13, 2026
SEATTLE MARINERS VS WASHINGTON NATIONALS JUNE 13, TIME & HOW TO WATCH | |
|---|---|
| Where | Nationals Park, Washington, D.C. |
| When | Saturday, June 13 – 4:05 PM ET |
| TV | Nationals.TV / Mariners TV (out-of-market via MLB.TV) |
Seattle Mariners vs. Washington Nationals Game Preview
The pitching matchup tilts toward Washington on paper. Right-hander Cade Cavalli (3-4, 3.88 ERA, 1.44 WHIP, 76 strikeouts) has become the Nationals' steadiest starter. He has allowed three earned runs or fewer in eight straight outings. In a recent win over Baltimore, he struck out eight across 6 1/3 innings while walking none. Seattle counters with veteran Luis Castillo (2-5, 5.16 ERA, 1.36 WHIP, 61 strikeouts). Castillo still misses bats, but his run prevention has been uneven this season. On price and recent form, the edge in the box belongs to Cavalli.
The standings tell a different story. Seattle enters first in the AL West at 37-34, while Washington sits fourth in the NL East at 35-35. The Mariners are 18-18 on the road. The Nationals, however, are just 12-21 at home and are trying to break a four-game home skid. Recent form is closer than the records suggest. Seattle is 5-5 over its last 10 with a 4.44 ERA. Washington is 4-6 over its last 10 with a 5.32 ERA.
Lineups matter here, and Seattle's is banged up. Catcher Cal Raleigh is on the 10-day injured list with a side issue, and infielders J.P. Crawford (hand) and Brendan Donovan (groin) are also out. Randy Arozarena, who leads the club with seven home runs and 33 RBIs, is day-to-day with a leg problem. Seattle still brings power, as the Mariners rank second in the AL with 93 home runs. Washington leans on outfielder James Wood, who has 19 homers and 34 extra-base hits.
SEATTLE MARINERS VS WASHINGTON NATIONALS ODDS | |||
|---|---|---|---|
| Run Line | Moneyline | Total | |
| SEATTLE MARINERS | -1.5 (+150) | -110 | U 9.0 (-115) |
| WASHINGTON NATIONALS | +1.5 (-175) | -110 | O 9.0 (-105) |
Odds accurate as of June 13, 2026 via TheSpread.com. Odds change, get the latest MLB Odds - Futures - Props
SEATTLE MARINERS VS WASHINGTON NATIONALS WHO IS THE PUBLIC BETTING? | |||
|---|---|---|---|
| SEATTLE MARINERS | 62% | 38% | WASHINGTON NATIONALS |
See the latest MLB Public Betting Splits and make smarter wagers!
Moneyline Pick — Washington Nationals ML
This game opened near a pick'em, and it has stayed there. The run line offers Seattle at -1.5 (+150), but laying a run and a half on the road in a coin-flip spot is shaky. As a result, the cleaner play is the moneyline. At -110 on both sides, we want the team with the situational edge, and that points to Washington.
The Pick: Washington Nationals Moneyline (-110)
The case for Washington starts on the mound. Cavalli carries the lower ERA and the better recent form, and he gets a Seattle lineup missing its best hitter in Raleigh. The Nationals are also at home, where pricing usually builds in an edge that the even number does not reflect here. On top of that, the public sits 60% on Seattle's moneyline and 62% on the Mariners' run line, so Washington is the modest contrarian side. That blend of a pitching edge, home field, and a banged-up opponent is worth a small price.
The case against is real, though. Seattle is the better team by record, leads its division, and brings more thump in the lineup. Washington has been poor at home and owns a 5.32 ERA over its last 10 games. If Castillo carries his recent swing-and-miss into this start, the Mariners can win outright behind that power. Still, at a true pick'em price, we will take the steadier arm and the home dog-in-disguise.
Total Pick — Under 9
The total opened at 8.5 and ticked up to 9.0, with the under priced at -115. That movement suggests the market expects runs, which often creates value on the quieter side. We lean under here for two reasons. First, Cavalli has limited damage in eight straight starts. Second, Seattle's lineup is thinned out without Raleigh, Crawford, and Donovan, which trims the Mariners' run-scoring ceiling.
The Pick: Under 9.0 (-115)
The other side deserves a hearing. Both bullpens have leaked runs lately, and Washington's staff owns that ugly 5.32 ERA over its last 10. Seattle still ranks second in the AL in home runs, so one swing can flip the math fast. The number moving up to nine is a warning sign. Even so, two starters who can miss bats, plus a shorthanded Seattle order, make the under the side we prefer at this price.
Final Thoughts and Bonus Angle
If you want one more angle, the starting-pitching gap points to a first-five-innings lean on Washington. The Nationals get the better arm before either bullpen enters, and the early frames are where Cavalli's edge over Castillo shows up most clearly. That said, Castillo's strikeout stuff can erase the gap in a hurry, so treat this as a smaller, secondary position rather than a featured play.
Bonus Angle: Washington Nationals, first five innings
Pull it together and this is a low-confidence, value-driven card built around a pick'em price and a clear pitching edge. Watch Arozarena's status before first pitch, since his bat changes Seattle's lineup math. For more of our daily coverage, see our latest MLB best bets roundup and our look at whether the Mariners could take their series in Baltimore. Here are the picks in one place:
- Moneyline: Washington Nationals (-110)
- Total: Under 9.0 (-115)
- Bonus: Washington Nationals, first five innings
MLB Nationals Prediction FAQ
What time does the Mariners vs. Nationals game start?
First pitch is set for 4:05 PM ET on Saturday, June 13, 2026, at Nationals Park in Washington, D.C.
What channel is the Mariners vs. Nationals game on?
The game airs regionally on Nationals.TV and Mariners TV, and it is available out of market through MLB.TV.
Who is pitching for the Mariners and Nationals?
Seattle starts right-hander Luis Castillo (2-5, 5.16 ERA), while Washington counters with right-hander Cade Cavalli (3-4, 3.88 ERA).
Who is favored in the Mariners vs. Nationals game?
The moneyline is a pick'em, with both teams listed at -110. Seattle is favored on the run line at -1.5 (+150), with Washington at +1.5 (-175).
What is the over/under for the Mariners vs. Nationals game?
The total is set at 9.0 runs. The over is priced at -105 and the under at -115.