Skip to main content
MLB Deserve-to-Win
← All pitchers·All hitters

Eduardo Rivera

2026
Red Sox· LHP · throws L· 10.0 IP· 6.30 ERA· 1.40 WHIP· 44 BF

Grade

How good he's been, and at what
Starter

A profile still coming into focus

Not enough modeled data yet to judge his run prevention with confidence.

44 batters faced · data through 2026-08-24.

How to read this chart
Each spoke is a skill estimate adjusted for sample size (not raw season stats), so farther out = better. Spokes are the metric itself; ↓ marks a rate where a LOWER number is better. Percentiles vs. 464 qualified pitchers — 100+ batters faced, starters and relievers pooled. He hasn't reached that bar himself, so he is measured against them rather than counted among them.

Pitcher type

What kind of pitcher he is, next to the league

Arsenal

What he throws, and what it does

Eduardo Rivera leans on his four-seam fastball (54% of pitches). His best pitch has been the four-seam fastball, saving 3.5 bases per 100 thrown vs average.

Pitch mix & swing-and-miss

+8 bases better than a replacement arm this season

allowed 17 bases vs a replacement arm's 25 over the same batters faced

Replacement level is per-batter and can't be split by pitch type, so the bars below use league average.

All pitches

4.4 bases saved vs league average, across 179 pitches — 2.5 per 100.

Four-Seam Fastball
54%
95.3 mph · LHP median 93.6
22% whiffs · Lg median 21%
saved 3.5 per 1004.0 total
Slider
31%
87.8 mph · LHP median 85.9
—
saved 0.6 per 1000.4 total
Changeup
not charted
15%
86.9 mph · LHP median 85.1
—
—

His changeup isn't in the charts below — only 31 of them were tracked with velocity and movement data this season.

How to read this chart
What they throw, how hard, and what misses bats — from pitch tracking, regular season only.

Mix by batter side

Compared with the league, his four-seam fastball tilts 16 points more toward lefties.

Four-Seam Fastball
59% vs LHH · LHP median 33%
50% vs RHH · LHP median 40%
Slider
40% vs LHH · LHP median 34%
24% vs RHH · LHP median 19%
How to read this chart
How the mix shifts against lefty and righty bats. Medians are among left-handed pitchers who throw that pitch at least 3% of the time — between 87 and 130 of them, depending on the pitch. Overall results by batter side are under Platoon splits.

By appearance

How the stuff has held up outing to outing

One point per outing — how his velocity, movement, and pitch mix have moved across the season, with league context for scale. Each pitch keeps the same color in every chart. His changeup isn't in these charts — only 31 of them were tracked with velocity and movement data this season.

Platoon splits

How he fares against lefties and righties

Platoon splits (EB/PA allowed)

Better vs LHB than vs RHB by 0.039 EB/PA allowed (modeled).

50% probable range: +0.030 to +0.048

vs LHB20 PA0.445

vs LHB: shrunk estimate 0.445 EB/PA, 50% probable range 0.422 to 0.468, based on 20 plate appearances. Raw (unshrunk) rate: 0.374 EB/PA. League median vs LHB: 0.453 EB/PA.

Raw vs LHB rate (0.374) is off this scale — small samples like this are exactly why the shrunk estimate (the dot) is the trustworthy number, not the raw one.

vs RHB24 PA0.483

vs RHB: shrunk estimate 0.483 EB/PA, 50% probable range 0.460 to 0.505, based on 24 plate appearances. Raw (unshrunk) rate: 0.436 EB/PA. League median vs RHB: 0.439 EB/PA.

0.4130.4380.4640.4890.514
← betterworse →
Below league medianAbove50% probable rangeHis raw rateMiddle half of the league

About the typical split for a lefty arm (median 0.038). Against righty bats he allows more than the league median — a genuine platoon vulnerability.

How to read this chart
  • Tap or hover any mark for its number, or tab to a row for all of them.
  • His raw rate is the unshrunk number against that side — small samples make it noisy, which is why the model pulls his estimate toward a more trustworthy value.
  • “Middle half of the league” is the 25th–75th percentile of all pitchers against that side.
  • These are bases allowed, so lower is better. Weighted by how often he faces each side, the two splits average back to his modeled overall EB/PA allowed — not the xEB/PA headline at the top of the page, which folds in strikeouts and walks differently.
  • Shrunk splits beat raw splits on held-out seasons, most decisively at low batters-faced counts (relievers especially), and converge with the raw numbers as exposure builds.

Contact allowed

What hitters do when they connect

Batters go to the pull side off him most often, and that's where the hardest contact comes from.

Pull and oppo are relative to each batter's stance, so this pools all the hitters he faced.

Batted balls allowed

Where every ball hit off Eduardo Rivera landed this season.
hit · out
EBlowhigh
vs Junior CamineroHome run
EV 112 mph · LA 26° · EB 3.8
07/17 vs Rays
vs Johnathan RodríguezDouble
EV 100 mph · LA 20° · EB 1.5
07/22 vs Orioles
vs Dylan BeaversSingle
EV 95 mph · LA 14° · EB 1.1
07/22 vs Orioles
vs Pete AlonsoDouble
EV 103 mph · LA 16° · EB 1.0
07/22 vs Orioles
vs Jorge PolancoSingle
EV 86 mph · LA 19° · EB 0.7
07/11 vs Mets

Luck check

Burned once — a ball with a hit probability under 20% that found grass anyway.

vs José CaballeroSingleCheap hit
EV 104 mph · LA 2° · EB 0.2 · xBA .197
04/22 vs Yankees
How to read this chart
Dot color is estimated bases (EB) — what the contact was worth, regardless of what the defense did with it. So a dark hollow ring in the outfield is a crushed ball his defense ran down. Tap or hover a dot or a row to link the two, and use the ▶ links to watch a play on Baseball Savant.

Best games

His biggest outings this year

Best games

His best outings this season by bases saved vs a replacement arm.