Arizona Diamondbacks at Boston Red Sox, MLB forecast
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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
Diamondbacks- Gabriel MorenoBatting1-3, 1 HR, 4 RBI
- Merrill KellyPitching4.0 IP, 6 ER, 2 K
Red Sox- Adley RutschmanBatting2-4, 1 HR, 3 RBI
- Ranger SuarezPitching5.1 IP, 4 ER, 3 K
Scoring summary
- 7Gasper singled to left, Duran scored.4–9
- 6Contreras reached on infield single to second, Sogard scored.4–8
- 6Gasper homered to center (414 feet).4–7
- 5Monasterio singled to left, Contreras scored, Rutschman thrown out at home.4–6
- 3Durbin scored on Kelly wild pitch.4–5
- 3Durbin scored on Kelly wild pitch.4–5
- 3Rutschman homered to right (401 feet).4–4
- 3Moreno homered to center (428 feet), Waldschmidt scored, Vargas scored and Carroll scored.4–3
- 1Durbin hit sacrifice fly to right, Abreu scored.0–3
- 1Rutschman singled to right, Rafaela scored and Sogard scored, Abreu to third.0–2
The pick
Reconstructed from what was known before the game: the ratings at that point and the closing line.
Red Sox 60%
Forecast Elo ratings alone
How often that comes true: MLB favorites the forecast gave 60–65% have won 61.6% of 1,194 graded games.
- Market
- BOS 60%
- ML ARI +148 / BOS -159
- Pre-line forecast
- BOS 62%
- Elo + market-implied
- Elo ratings
- BOS 56%
- Ratings vs. market
- −4.3 pts
- BOS: Elo 56.0%, market 60.4%
- Fair odds
- BOS -152
- ARI +152 · the forecast as odds, no margin
- Pregame projection
- ARI 3.3 – 4.2 BOS
- Margin from the forecast, posted total 7.5
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 | ARI | BOS | Why |
|---|---|---|---|
| Team rating | 1512 | 1543 | Elo entering the game; 1500 is league average |
| Home field | — | +18 | Worth 18 Elo in MLB |
| Starting pitchers | −4 | −11 | ARI: Merrill Kelly: team allows 0.21 more runs than with its usual starter (≈10 weighted starts) · BOS: Ranger Suarez: team allows 0.56 more runs than with its usual starter (≈10 weighted starts) |
| Elo ratings | BOS +42 Elo | BOS 56.0% | |
| Market-implied ratings | BOS 62.8% | Team strength as past closing lines priced it, same game context | |
| Pre-line forecast | BOS 61.8% | 15% Elo, 85% market-implied (log-odds blend) | |
| Forecast | BOS 60.4% | 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.
| ARI | Stat | BOS |
|---|---|---|
| 14th of 304.5 | Runs scored | 4.516th of 30 |
| 17th of 304.4 | Runs allowed | 3.82nd of 30 |
| 15th of 30+0.1 | Margin | +0.75th of 30 |
| 12th of 305–5 | Last 10 | 3–728th of 30 |
| 14th of 3030–33 | Road vs home | 30–3121st of 30 |
| 13th of 301500 | Opponent Elo | 150111th of 30 |
| 11th of 301512 | Elo rating | 15434th 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 |  ARI |  BOS |
|---|---|---|
| Run line | 69–57 | 63–62 |
| Last 10 | 6–4 | 3–7 |
| Favorite | 20–33 | 34–45 |
| Underdog | 49–24 | 29–17 |
| Overs–unders | 51–67–8 | 57–64–4 |
| 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
ARI 6–4 BOS in their last 10 meetings; the forecast called 2 of 10.