San Francisco Giants 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
Giants- Willy AdamesBatting1-1, 1 HR, 1 RBI
- Robbie RayPitching4.1 IP, 9 ER, 1 K
Diamondbacks- Nolan ArenadoBatting1-4, 1 HR, 4 RBI
- Zac GallenPitching6.0 IP, 2 ER, 5 K
Scoring summary
- 5Marte scored on error, Arenado safe at first on fielding error by shortstop Adames, Perdomo safe at third on error.2–12
- 5Marte reached on infield single to first, Waldschmidt scored.2–11
- 5Waldschmidt doubled to left, Fernandez scored.2–10
- 5Moreno homered to left (398 feet), Vargas scored.2–9
- 3Tawa singled to center, Vargas scored and Moreno scored.2–7
- 3Arraez hit sacrifice fly to right, Bader scored.2–5
- 2Marte hit sacrifice fly to center, Waldschmidt scored.1–5
- 2Adames homered to left (388 feet).1–4
- 1Arenado homered to left (403 feet), Marte scored, Carroll scored and Perdomo scored.0–4
The pick
Reconstructed from what was known before the game: the ratings at that point and the closing line.
Diamondbacks 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
- ARI 55%
- ML SF +114 / ARI -137
- Pre-line forecast
- ARI 54%
- Elo + market-implied
- Elo ratings
- ARI 54%
- Ratings vs. market
- −1.1 pts
- ARI: Elo 54.2%, market 55.3%
- Fair odds
- ARI -124
- SF +124 · the forecast as odds, no margin
- Pregame projection
- SF 4.3 – 4.7 ARI
- Margin from the forecast, posted total 9
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 | SF | ARI | Why |
|---|---|---|---|
| Team rating | 1490 | 1503 | Elo entering the game; 1500 is league average |
| Home field | — | +18 | Worth 18 Elo in MLB |
| Starting pitchers | +8 | +6 | SF: Robbie Ray: team allows 0.42 fewer runs than with its usual starter (≈10 weighted starts) · ARI: Zac Gallen: team allows 0.30 fewer runs than with its usual starter (≈10 weighted starts) |
| Elo ratings | ARI +29 Elo | ARI 54.2% | |
| Market-implied ratings | ARI 54.2% | Team strength as past closing lines priced it, same game context | |
| Pre-line forecast | ARI 54.2% | 15% Elo, 85% market-implied (log-odds blend) | |
| Forecast | ARI 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.
| SF | Stat | ARI |
|---|---|---|
| 30th of 303.5 | Runs scored | 4.414th of 30 |
| 12th of 304.3 | Runs allowed | 4.824th of 30 |
| 26th of 30−0.8 | Margin | −0.420th of 30 |
| 7th of 306–4 | Last 10 | 5–513th of 30 |
| 21st of 3010–15 | Road vs home | 11–810th of 30 |
| 1st of 301513 | Opponent Elo | 15076th of 30 |
| 19th of 301490 | Elo rating | 150314th 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 |  SF |  ARI |
|---|---|---|
| Run line | 23–24 | 26–19 |
| Last 10 | 5–5 | 5–5 |
| Favorite | 6–8 | 8–11 |
| Underdog | 17–16 | 18–8 |
| Overs–unders | 20–24–3 | 21–20–4 |
| Overs–unders, last 10 | 5–5 | 3–7 |
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
SF 18–21 ARI in their last 39 meetings; the forecast called 25 of 39.