MLB Preview · May 9, 2026

Tampa Bay Rays at Boston Red Sox: Prediction, Odds & Preview

TB 56-38at BOS 46-48·Fenway Park·

DiamondIQ Model — Win Probability

TB51.6%48.4%BOS

The model leans TB (51.6%). DiamondIQ model v2: season records, home-field advantage, the starting-pitcher quality gap (PitchIQ), and a calibration adjustment fit and validated on four seasons of backtest — plus live game state once underway.

The Matchup

Tampa Bay heads into Fenway Park as a clear favorite despite playing on the road, with the DiamondIQ model's estimate putting the Rays at 60.3% and the Red Sox at 39.7%. That gap is largely a reflection of the standings, where Tampa Bay's 52-35 mark dwarfs Boston's 40-48 record. It is worth noting the model relies strictly on team records and home field, setting aside the pitching matchup entirely, which makes the starting arms a meaningful independent layer of analysis here.

The pitching matchup tilts decisively toward Boston on paper. Payton Tolle carries a DiamondIQ PitchIQ of 61 out of 100, rated above average, and his surface numbers back that up with a 3.39 ERA, 1.12 WHIP, and a 24.3 strikeout percentage across 74.1 innings. His four-seamer sits at 96.0 mph and generates a 27 percent whiff rate with a strong 0.255 wOBA allowed, making it a genuine swing-and-miss weapon. His sinker is a vulnerability, however, carrying a 0.409 wOBA allowed on 23 percent usage. Nick Martinez presents the more complicated profile. His ERA of 2.61 and WHIP of 1.13 over 100.0 innings are genuinely impressive results, yet his DiamondIQ PitchIQ of 40 out of 100 signals below-average stuff by Statcast measures. His changeup is his best weapon at 35 percent whiff and a 0.176 wOBA allowed, while his sinker and cutter are more hittable at 0.307 and 0.327 wOBA respectively. His 15.0 strikeout percentage is modest, meaning Martinez relies on contact management rather than overpowering hitters.

Conditions at Fenway favor offense, with an 81-degree first pitch, an 11 mph wind blowing out to center field, and just 3 percent precipitation. That wind could amplify any mistakes left over the plate, putting additional pressure on Martinez's contact-heavy approach given his cutter and sinker wOBA numbers. Both bullpens are in comparable shape, with the Rays holding a slight BullpenIQ edge at 54 versus Boston's 52, and Tampa Bay carrying five fresh arms to Boston's four. The model leans toward the Rays on record strength, but the thing to watch is whether Tolle's four-seamer can generate the kind of whiff volume needed to keep Tampa Bay's lineup from doing enough damage against a Fenway outflow wind to overcome the results gap Martinez has built so far this season.

Analysis generated by DiamondIQ's model.

Probable Pitchers

TB
ERA
2.65
WHIP
1.12
K%
14.5
BB%
4.4
K/9
5.30
IP
105.1
Arsenal
Sinker 31% · 93mphChangeup 28% · 78mphCutter 20% · 89mphFour-Seam 12% · 93mphCurveball 7% · 80mph
BOS
ERA
3.11
WHIP
1.07
K%
25.5
BB%
7.3
K/9
9.32
IP
84.0
Arsenal
Four-Seam 49% · 96mphSinker 22% · 95mphCutter 18% · 88mphCurveball 8% · 82mphChangeup 3% · 89mph

Forecast at First Pitch

☀️83°FClear
Wind 13 mph WNW · L→R
Precip 0%

Injured List

TB
Jake Fraley (RF)Injured 10-Day
Jesse Scholtens (P)Injured 15-Day
Steven Matz (P)Injured 15-Day
Edwin Uceta (P)Injured 60-Day
Gavin Lux (LF)Injured 60-Day
Jonathan Heasley (P)Injured 60-Day
BOS
Isiah Kiner-Falefa (2B)Injured 10-Day
Marcelo Mayer (2B)Injured 10-Day
Connelly Early (P)Injured 15-Day
Ranger Suarez (P)Injured 15-Day
Garrett Crochet (P)Injured 60-Day
Johan Oviedo (P)Injured 60-Day
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