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- Brice MatthewsBatting1-4, 1 HR, 2 RBI
- Framber ValdezPitching7.0 IP, 1 ER, 4 K
Diamondbacks- Randal GrichukBatting3-3
- Eduardo RodriguezPitching6.1 IP, 0 ER, 3 K
Scoring summary
- 9Altuve scored on Backhus wild pitch, Whitcomb to second on wild pitch by Backhus, Diaz to third on wild pitch by Backhus.3–1
- 9Altuve scored on Backhus wild pitch, Whitcomb to second on wild pitch by Backhus, Diaz to third on wild pitch by Backhus.3–1
- 8Matthews homered to left (396 feet), Trammell scored.2–1
- 5Alexander grounded out to second, Grichuk scored, Perdomo to second.0–1
The pick
Reconstructed from what was known before the game: the ratings at that point and the closing line.
Astros 52%
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
- HOU 52%
- ML HOU -115 / ARI +100
- Pre-line forecast
- HOU 52%
- Elo + market-implied
- Elo ratings
- HOU 54%
- Ratings vs. market
- +2.2 pts
- HOU: Elo 53.9%, market 51.7%
- Fair odds
- HOU -107
- ARI +107 · the forecast as odds, no margin
- Pregame projection
- HOU 4.3 – 4.2 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 | 1535 | 1517 | Elo entering the game; 1500 is league average |
| Home field | — | +18 | Worth 18 Elo in MLB |
| Starting pitchers | +18 | −9 | HOU: Framber Valdez: team allows 0.89 fewer runs than with its usual starter (≈10 weighted starts) · ARI: Eduardo Rodriguez: team allows 0.47 more runs than with its usual starter (≈10 weighted starts) |
| Elo ratings | HOU +27 Elo | HOU 53.9% | |
| Market-implied ratings | HOU 51.3% | Team strength as past closing lines priced it, same game context | |
| Pre-line forecast | HOU 51.7% | 15% Elo, 85% market-implied (log-odds blend) | |
| Forecast | HOU 51.7% | 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 | 5.025th of 30 |
| 8th of 30+0.6 | Margin | +0.215th of 30 |
| 25th of 303–7 | Last 10 | 5–511th of 30 |
| 4th of 3025–23 | Road vs home | 26–2622nd of 30 |
| 25th of 301496 | Opponent Elo | 150017th of 30 |
| 6th of 301535 | Elo rating | 151713th 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 | 48–52 | 53–48 |
| Last 10 | 3–7 | 7–3 |
| Favorite | 25–42 | 27–34 |
| Underdog | 23–10 | 26–14 |
| Overs–unders | 45–55 | 56–45 |
| Overs–unders, last 10 | 7–3 | 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 6–1 ARI in their last 7 meetings; the forecast called 2 of 7.