MLB matchup analysis
Diamondbacks vs Red Sox Prediction, Odds and Model Pick
Tuesday, August 18, 2026 at Fenway Park · 7:10 PM ET
LyDia prediction: Boston Red Sox moneyline
The case for Boston Red Sox
The case for Arizona Diamondbacks
Why it is not official
Why the setup score is what it is
Read the full model output
Boston Red Sox remains on the watchlist. Lab Rating 7.0/10: conviction 20, pitching plan 20, bullpen 6.57, offense 23.28. LyDia projects 74.0% against a 60.1% no-vig market number, a 13.9% model edge at -160. Boston Red Sox owns the starting pitcher edge by 23 points. Bullpen read: Adds caution. Boston Red Sox's pen efficiency: Effective (5.9/10). Lineup check: Boston Red Sox is swinging a hot bat (+0.100 OPS); Arizona Diamondbacks is swinging a hot bat (+0.060 OPS).
Game information
| Matchup | Arizona Diamondbacks at Boston Red Sox |
|---|---|
| Date | Tuesday, August 18, 2026 |
| First pitch | 7:10 PM ET |
| Venue | Fenway Park |
| Starting pitchers | Merrill Kelly vs Ranger Suarez |
| Weather | Game-time forecast: 74°F, 1% precipitation chance, 6 mph wind from E. |
Starting pitcher matchup
Full Pitcher Matchup Tool →| Metric | Diamondbacks | Red Sox |
|---|---|---|
| Pitching plan | Traditional starter | Traditional starter |
| Expected innings | 5⅔ | 5 |
| Throws | R | L |
| LyDia pitcher score (higher is better) | 50 | 73 |
| ERA (lower is better) | 5.11 | 3.25 |
| WHIP (lower is better) | 1.48 | 1.19 |
| K/9 (higher is better) | 5.9 | 9.2 |
| K-BB% (higher is better) | 5.4% | 17.8% |
| K% (higher is better) | 15.1% | 24.7% |
| BB% (lower is better) | 9.8% | 7.0% |
| BB/9 (lower is better) | 3.8 | 2.6 |
| HR/9 (lower is better) | 1.8 | 0.5 |
| Ground-ball rate | 47.6% | 48.5% |
| Fly-ball rate | 52.4% | 51.5% |
Pitcher edge: LyDia gives Ranger Suarez a 23-point edge over Merrill Kelly, driven mainly by HR/9 (0.50 vs 1.80) and K-BB% (17.8% vs 5.4%).
How to read this: the scorecards above name the starters; every number lives in this table. Highlighted cells mark a gap big enough to matter. K% and BB% are strikeout and walk rate as a share of batters faced -- K-BB% is the two combined into one skill number. HR/9 is home runs allowed per nine innings. Ground-ball and fly-ball rate are neither good nor bad on their own: high ground-ball pitchers trade strikeouts for double plays and fewer home runs, and on this data source the two rates are complementary (they add to 100%), not independent reads.
Strikeout Projections Full strikeout projections →
Same data source as the Pitcher Matchup Tool, where every starter on the slate is compared side by side.
Recent form
Full Stats page →Diamondbacks are 5-5 in their last 10, averaging 4.3 runs per game over the last 15 days, and swinging above their season form; Red Sox are 3-7 in their last 10, averaging 6.1 runs per game over the last 15 days, and swinging above their season form. On the season Red Sox carry the better run differential per game (+0.73 against +0.06).
| Metric | Diamondbacks | Red Sox |
|---|---|---|
| Last 10 | 5-5 | 3-7 |
| Last 10 by venue (away team on the road, home team at home) | 6-4 on the road | 7-3 at home |
| OPS, last 15 days | 0.772 | 0.824 |
| wOBA, last 15 days (hot/cold read) | 0.336 | 0.357 |
| Runs per game, last 15 days | 4.3 | 6.1 |
| K% last 15 days (lower is better) | 19.2% | 18.6% |
Last 15 days only. Hot and cold streaks for all 30 teams live on the Stats page.
30-day offense
Full offense tool →| Last 30 days | Diamondbacks | Red Sox |
|---|---|---|
| OPS | 0.779 (+0.067 vs szn) | 0.777 (+0.053 vs szn) |
| Runs per game | 5.11 (+0.599 vs szn) | 5.46 (+0.984 vs szn) |
| wOBA (model offense input) | 0.341 (+0.026 vs szn) | 0.340 (+0.020 vs szn) |
| K% (lower is better) | 18.1% (-1.2% vs szn) | 20.6% (-1.0% vs szn) |
Over the last 30 days the Diamondbacks have been the better offense, 0.341 wOBA to 0.340. They are running hot against their own season line (+0.026 wOBA).
Season profile
Full Stats page →| Metric | Diamondbacks | Red Sox |
|---|---|---|
| Record | 66-60 | 67-58 |
| Run differential / game (team quality) | +0.06 | +0.73 |
| Runs scored / game (offense, season) | 4.51 | 4.48 |
| Runs allowed / game (defense, season, lower better) | 4.44 | 3.75 |
| Season OPS | 0.712 | 0.724 |
| K% season (lower is better) | 19.3% | 21.6% |
| OPS vs opposing hand (season) | 0.786 | 0.711 |
Season-long team quality, not recent form. Run differential and run environment come from the season standings; splits for all 30 teams live on the Stats page, including the run environment table.
The Map
Full interactive map →Every team on today's slate, on any two axes you pick. Diamondbacks and Red Sox are highlighted.
Bullpen matchup
Full Bullpen Fatigue Index →Risk is what the model actually uses: fatigue blended with how well the pen has pitched. High fatigue with high efficiency is a tired pen that is still getting outs.
| Metric | Diamondbacks | Red Sox |
|---|---|---|
| Fatigue | 5.2/10, Normal | 7.5/10, Tired |
| Efficiency | 4.5/10, Average | 5.9/10, Effective |
| Combined risk | 5.5/10, Normal | 7.1/10, Tired |
| Relief innings, last 7 days | 19.3 | 25.0 |
| Back-to-back arms | 3 | 5 |
| 7-day ERA | 5.12 | 3.60 |
| 7-day WHIP | 1.24 | 0.96 |
Fatigue measures workload. Efficiency measures recent run prevention. Combined risk is what the moneyline and totals systems use.
Run total projection
Full Totals Projections →The model and market are close. Team totals remain research-only until their graded sample is established.
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