Seattle Mariners at Boston Red Sox, 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 BOS.
Game center
From the ESPN box score.
Top performers
Mariners- Josh RojasBatting2-5, 1 HR, 1 RBI
- George KirbyPitching5.1 IP, 2 ER, 2 K
Red Sox- Rafael DeversBatting3-5, 1 RBI
- Brayan BelloPitching6.1 IP, 2 ER, 7 K
Scoring summary
- 10Devers doubled to right, O'Neill scored.2–3
- 10Pitch 3 : Ball In Play2–3
- 10Pitch 2 : Ball 22–3
- 10Pitch 1 : Ball 12–3
- 6D. Jansen singled to right, Smith scored.2–2
- 6Pitch 2 : Ball In Play2–2
- 6Pitch 1 : Ball 12–2
- 5Rojas homered to center (407 feet).2–1
- 5Pitch 2 : Ball In Play2–1
- 5Pitch 1 : Ball 12–1
- 4Moore singled to left, Raleigh scored, Polanco to second.1–1
- 4Pitch 2 : Ball In Play1–1
- 4Pitch 1 : Strike 1 Foul1–1
- 1Yoshida scored on Kirby wild pitch, Devers to third on wild pitch by Kirby.0–1
- 1Yoshida scored on Kirby wild pitch, Devers to third on wild pitch by Kirby.0–1
The pick
Reconstructed from what was known before the game: the ratings at that point and the closing line.
Mariners 51%
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 51%
- ML SEA -115 / BOS -105
- Pre-line forecast
- SEA 49%
- Elo + market-implied
- Elo ratings
- SEA 52%
- Ratings vs. market
- +1.4 pts
- SEA: Elo 52.5%, market 51.1%
- Fair odds
- SEA -104
- BOS +104 · the forecast as odds, no margin
- Pregame projection
- SEA 4.8 – 4.7 BOS
- Margin from the forecast, posted total 9.5
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 | SEA | BOS | Why |
|---|---|---|---|
| Team rating | 1516 | 1501 | Elo entering the game; 1500 is league average |
| Home field | — | +18 | Worth 18 Elo in MLB |
| Starting pitchers | +6 | −14 | SEA: George Kirby: team allows 0.30 fewer runs than with its usual starter (≈10 weighted starts) · BOS: Brayan Bello: team allows 0.69 more runs than with its usual starter (≈10 weighted starts) |
| Elo ratings | SEA +17 Elo | SEA 52.5% | |
| Market-implied ratings | BOS 51.9% | Team strength as past closing lines priced it, same game context | |
| Pre-line forecast | BOS 51.2% | 15% Elo, 85% market-implied (log-odds blend) | |
| Forecast | SEA 51.1% | 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.
| SEA | Stat | BOS |
|---|---|---|
| 28th of 303.9 | Runs scored | 4.97th of 30 |
| 2nd of 303.7 | Runs allowed | 4.722nd of 30 |
| 16th of 30+0.2 | Margin | +0.215th of 30 |
| 14th of 305–5 | Last 10 | 3–725th of 30 |
| 18th of 3026–29 | Road vs home | 26–2924th 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 |  SEA |  BOS |
|---|---|---|
| Run line | 45–62 | 48–59 |
| Last 10 | 4–6 | 4–6 |
| Favorite | 26–46 | 20–40 |
| Underdog | 19–16 | 28–19 |
| Overs–unders | 45–60–2 | 53–52–2 |
| Overs–unders, last 10 | 5–5 | 9–1 |
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
SEA 6–6 BOS in their last 12 meetings; the forecast called 8 of 12.