Houston Astros 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
Astros- Christian WalkerBatting2-5, 1 RBI
- Brandon WalterPitching7.0 IP, 1 ER, 5 K
Diamondbacks- Ketel MarteBatting2-5, 1 HR, 1 RBI
- Brandon PfaadtPitching5.1 IP, 2 ER, 5 K
Scoring summary
- 9Walker singled to center, Short scored, Trammell to third.4–3
- 8Naylor singled to right, Marte scored, Suárez to second, Carroll to third.3–3
- 8Carroll doubled to right, Perdomo scored, Marte to third.3–2
- 8Dubón singled to left, Diaz scored.3–1
- 6Diaz scored on Saalfrank wild pitch, Matthews to second on wild pitch by Saalfrank.2–1
- 6Diaz scored on Saalfrank wild pitch, Matthews to second on wild pitch by Saalfrank.2–1
- 6Walker scored on error, Matthews safe at first on fielding error by shortstop Perdomo.1–1
- 1Marte homered to left center (420 feet).0–1
The pick
Reconstructed from what was known before the game: the ratings at that point and the closing line.
Diamondbacks 57%
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 57%
- ML HOU +120 / ARI -145
- Pre-line forecast
- ARI 52%
- Elo + market-implied
- Elo ratings
- ARI 51%
- Ratings vs. market
- −5.3 pts
- ARI: Elo 51.2%, market 56.6%
- Fair odds
- ARI -130
- HOU +130 · the forecast as odds, no margin
- Pregame projection
- HOU 4.0 – 4.5 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 | HOU | ARI | Why |
|---|---|---|---|
| Team rating | 1536 | 1515 | Elo entering the game; 1500 is league average |
| Home field | — | +18 | Worth 18 Elo in MLB |
| Starting pitchers | −12 | −1 | HOU: Brandon Walter: team allows 0.62 more runs than with its usual starter (≈6 weighted starts) · ARI: Brandon Pfaadt: team allows 0.06 more runs than with its usual starter (≈10 weighted starts) |
| Elo ratings | ARI +9 Elo | ARI 51.2% | |
| Market-implied ratings | ARI 52.4% | Team strength as past closing lines priced it, same game context | |
| Pre-line forecast | ARI 52.2% | 15% Elo, 85% market-implied (log-odds blend) | |
| Forecast | ARI 56.6% | 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.
| HOU | Stat | ARI |
|---|---|---|
| 14th of 304.4 | Runs scored | 5.14th of 30 |
| 3rd of 303.8 | Runs allowed | 4.925th of 30 |
| 8th of 30+0.6 | Margin | +0.117th of 30 |
| 19th of 304–6 | Last 10 | 5–514th of 30 |
| 2nd of 3026–23 | Road vs home | 26–2723rd of 30 |
| 25th of 301497 | Opponent Elo | 150016th of 30 |
| 6th of 301536 | Elo rating | 151512th 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 |  HOU |  ARI |
|---|---|---|
| Run line | 49–52 | 53–49 |
| Last 10 | 4–6 | 6–4 |
| Favorite | 26–42 | 27–34 |
| Underdog | 23–10 | 26–15 |
| Overs–unders | 45–56 | 56–46 |
| Overs–unders, last 10 | 6–4 | 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
HOU 7–1 ARI in their last 8 meetings; the forecast called 3 of 8.