Boston Red Sox at Arizona Diamondbacks, 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 ARI.
Game center
From the ESPN box score.
Top performers
Red Sox- Alex BregmanBatting2-4, 2 RBI
- Payton TollePitching3.0 IP, 5 ER, 2 K
Diamondbacks- Geraldo PerdomoBatting4-5, 1 HR, 2 RBI
- Eduardo RodriguezPitching6.0 IP, 1 ER, 4 K
Scoring summary
- 8Carroll homered to right (375 feet), Barrosa scored and Perdomo scored.5–10
- 8Perdomo singled to center, Locklear scored, Barrosa to second.5–7
- 8Refsnyder doubled to center, Story scored.5–6
- 8González hit sacrifice fly to right, Bregman scored, Story to third.4–6
- 8Bregman doubled to left, Duran scored and Narváez scored.3–6
- 5Lawlar hit sacrifice fly to left, Moreno scored, Alexander to third.1–6
- 3Vargas homered to left (407 feet), Moreno scored and Alexander scored.1–5
- 2Lawlar scored on Tolle wild pitch.1–2
- 2Lawlar scored on Tolle wild pitch.1–2
- 2Lowe tripled to right, González scored.1–1
- 1Perdomo homered to center (417 feet).0–1
The pick
Reconstructed from what was known before the game: the ratings at that point and the closing line.
Red Sox 55%
Forecast Elo ratings alone
How often that comes true: MLB favorites the forecast gave 55–60% have won 55.5% of 2,596 graded games.
- Market
- BOS 55%
- ML BOS -135 / ARI +115
- Pre-line forecast
- BOS 52%
- Elo + market-implied
- Elo ratings
- BOS 49%
- Ratings vs. market
- −6.1 pts
- BOS: Elo 49.2%, market 55.3%
- Fair odds
- BOS -124
- ARI +124 · the forecast as odds, no margin
- Pregame projection
- BOS 4.5 – 4.0 ARI
- Margin from the forecast, posted total 8.5
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 | ARI | Why |
|---|---|---|---|
| Team rating | 1530 | 1514 | Elo entering the game; 1500 is league average |
| Home field | — | +18 | Worth 18 Elo in MLB |
| Starting pitchers | −3 | +2 | BOS: Payton Tolle: team allows 0.14 more runs than with its usual starter (≈1 weighted starts) · ARI: Eduardo Rodriguez: team allows 0.09 fewer runs than with its usual starter (≈10 weighted starts) |
| Elo ratings | ARI +6 Elo | ARI 50.8% | |
| Market-implied ratings | BOS 52.7% | Team strength as past closing lines priced it, same game context | |
| Pre-line forecast | BOS 52.2% | 15% Elo, 85% market-implied (log-odds blend) | |
| Forecast | BOS 55.3% | 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 | ARI |
|---|---|---|
| 6th of 304.9 | Runs scored | 4.97th of 30 |
| 11th of 304.2 | Runs allowed | 4.824th of 30 |
| 5th of 30+0.7 | Margin | +0.115th of 30 |
| 2nd of 307–3 | Last 10 | 6–47th of 30 |
| 10th of 3034–35 | Road vs home | 36–3319th of 30 |
| 14th of 301501 | Opponent Elo | 149624th of 30 |
| 6th of 301530 | Elo rating | 151412th 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 |  ARI |
|---|---|---|
| Run line | 74–67 | 73–68 |
| Last 10 | 4–6 | 8–2 |
| Favorite | 36–48 | 32–46 |
| Underdog | 38–19 | 41–22 |
| Overs–unders | 71–70 | 71–70 |
| Overs–unders, last 10 | 4–6 | 4–6 |
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 2–4 ARI in their last 6 meetings; the forecast called 1 of 6.