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- Trevor StoryBatting1-4, 1 HR, 2 RBI
- Garrett CrochetPitching6.0 IP, 1 ER, 8 K
Mariners- Dylan MooreBatting1-4
- Luis CastilloPitching6.0 IP, 3 ER, 5 K
Scoring summary
- 4Story homered to left center (402 feet), Mayer scored.3–1
- 2Arozarena scored on Crochet wild pitch.1–1
- 2Arozarena scored on Crochet wild pitch.1–1
- 2Mayer homered to right (379 feet).1–0
The pick
Reconstructed from what was known before the game: the ratings at that point and the closing line.
Red Sox 52%
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
- BOS 52%
- ML BOS -120 / SEA +100
- Pre-line forecast
- BOS 54%
- Elo + market-implied
- Elo ratings
- BOS 48%
- Ratings vs. market
- −4.6 pts
- BOS: Elo 47.5%, market 52.2%
- Fair odds
- BOS -109
- SEA +109 · the forecast as odds, no margin
- Pregame projection
- BOS 3.3 – 3.2 SEA
- Margin from the forecast, posted total 6.5
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 | 1504 | 1509 | Elo entering the game; 1500 is league average |
| Home field | — | +18 | Worth 18 Elo in MLB |
| Starting pitchers | +14 | +8 | BOS: Garrett Crochet: team allows 0.72 fewer runs than with its usual starter (≈10 weighted starts) · SEA: Luis Castillo: team allows 0.42 fewer runs than with its usual starter (≈10 weighted starts) |
| Elo ratings | SEA +17 Elo | SEA 52.5% | |
| Market-implied ratings | BOS 54.7% | Team strength as past closing lines priced it, same game context | |
| Pre-line forecast | BOS 53.7% | 15% Elo, 85% market-implied (log-odds blend) | |
| Forecast | BOS 52.2% | 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 |
|---|---|---|
| 6th of 304.7 | Runs scored | 4.412th of 30 |
| 22nd of 304.5 | Runs allowed | 4.319th of 30 |
| 15th of 30+0.2 | Margin | +0.118th of 30 |
| 1st of 308–2 | Last 10 | 5–516th of 30 |
| 18th of 3016–20 | Road vs home | 20–1820th of 30 |
| 14th of 301501 | Opponent Elo | 149228th of 30 |
| 17th of 301504 | Elo rating | 150914th 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 | 38–37 | 30–42 |
| Last 10 | 6–4 | 3–7 |
| Favorite | 16–26 | 12–33 |
| Underdog | 22–11 | 18–9 |
| Overs–unders | 35–40 | 39–33 |
| Overs–unders, last 10 | 4–6 | 6–4 |
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 9–9 SEA in their last 18 meetings; the forecast called 10 of 18.