Boston Red Sox at Seattle Mariners, MLB forecast
Win probability
Starts from the pregame forecast, then moves with the score and the time left after each inning. Above the line favors SEA.
Game center
From the ESPN box score.
Top performers
Red Sox- Wilyer AbreuBatting1-3, 1 HR, 2 RBI
- Connelly EarlyPitching6.0 IP, 1 ER, 7 K
Mariners- Josh NaylorBatting1-4, 1 RBI
- Emerson HancockPitching5.1 IP, 5 ER, 6 K
Scoring summary
- 6Mayer reached on infield single to second, Duran scored, Durbin to second.5–1
- 6Durbin reached on infield single to shortstop, Contreras scored, Duran to third.4–1
- 6Wild pitch by pitcher José A. Ferrer. Wilyer Abreu scores. Willson Contreras to 3rd. Jarren Duran to 2nd.3–1
- 6Abreu scored on Ferrer wild pitch, Duran to second on wild pitch by Ferrer, Contreras to third on wild pitch by Ferrer.3–1
- 4Abreu homered to center (414 feet), Seigler scored.2–1
- 1Naylor singled to center, Crawford scored, Rodríguez to second.0–1
The pick
Reconstructed from what was known before the game: the ratings at that point and the closing line.
Mariners 53%
Forecast Elo ratings alone
How often that comes true: MLB favorites the forecast gave 50–55% have won 52.7% of 2,871 graded games.
- Market
- SEA 53%
- ML BOS +105 / SEA -126
- Pre-line forecast
- SEA 52%
- Elo + market-implied
- Elo ratings
- SEA 52%
- Ratings vs. market
- −1.2 pts
- SEA: Elo 52.2%, market 53.3%
- Fair odds
- SEA -114
- BOS +114 · the forecast as odds, no margin
- Pregame projection
- BOS 3.4 – 3.6 SEA
- Margin from the forecast, posted total 7
How the number is built
Elo inputs in rating points (higher favors that team; 25–28 Elo is about a point of spread in football and basketball), then how the pieces combine.
| Factor | BOS | SEA | Why |
|---|---|---|---|
| Team rating | 1506 | 1518 | Elo entering the game; 1500 is league average |
| Home field | — | +18 | Worth 18 Elo in MLB |
| Starting pitchers | +8 | −6 | BOS: Connelly Early: team allows 0.38 fewer runs than with its usual starter (≈9 weighted starts) · SEA: Emerson Hancock: team allows 0.32 more runs than with its usual starter (≈10 weighted starts) |
| Elo ratings | SEA +15 Elo | SEA 52.2% | |
| Market-implied ratings | SEA 51.8% | Team strength as past closing lines priced it, same game context | |
| Pre-line forecast | SEA 51.9% | 15% Elo, 85% market-implied (log-odds blend) | |
| Forecast | SEA 53.3% | Follows the market (vig removed): in testing, adding the ratings made it less accurate | |
Tale of the tape
This season coming into the game, regular season, each number with its league rank (the longer the bar, the higher). Home and road: the host's record at home against the visitor's on the road. Opponent Elo: how strong the teams each has played are, 1st the toughest.
| BOS | Stat | SEA |
|---|---|---|
| 29th of 303.9 | Runs scored | 4.221st of 30 |
| 7th of 304.1 | Runs allowed | 3.95th of 30 |
| 17th of 30−0.1 | Margin | +0.26th of 30 |
| 30th of 303–7 | Last 10 | 4–619th of 30 |
| 11th of 3018–18 | Road vs home | 21–1812th of 30 |
| 4th of 301507 | Opponent Elo | 149327th of 30 |
| 11th of 301506 | Elo rating | 15187th of 30 |
Rating history
Each team's Elo over the last two seasons. Hover or drag to compare on any date.
Recent form
Last five results, and whether the forecast hit.
Against the line
How each team has done against the closing spread and total, coming into this game.
| This season |  BOS |  SEA |
|---|---|---|
| Run line | 31–42 | 33–44 |
| Last 10 | 4–6 | 4–6 |
| Favorite | 14–28 | 24–37 |
| Underdog | 17–14 | 9–7 |
| Overs–unders | 33–37–3 | 37–36–4 |
| Overs–unders, last 10 | 5–5 | 7–2–1 |
Against each game's closing line. Books set every line knowing these records: across 3,901 past games, the team with the better record against the spread so far that season covered 51.2%, short of the 52.4% a standard −110 bet needs, and over/under streaks held 48.0% of the time. They describe the past.
Head to head
BOS 11–9 SEA in their last 20 meetings; the forecast called 11 of 20.