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MLB Deserve-to-Win
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Cooper Hjerpe

2026
Cardinals· LHP · throws L· 12.1 IP· 4.38 ERA· 1.30 WHIP· 55 batters faced

Grade

His grade shows how good he has been, and at what.
Starter

His grade is not ready yet

The simulator does not have enough data yet to grade how well he limits bases.

His grade rests on 55 batters faced, with data through 2026-09-27.

How to read this chart
Each spoke is a skill estimate adjusted for sample size, not a raw season stat, and farther out is better. A ↓ marks a stat where a lower number is better, and its spoke is flipped so farther out still means better. The middle ring marks the league median and the outer ring the league best. Percentiles compare him with 517 qualified pitchers, those with 100+ batters faced, starters and relievers together. He has not reached that bar himself, so he is measured against them rather than counted among them.

Pitcher type

This map shows what kind of pitcher he is, next to the league.

Arsenal

These cards show what he throws and what each pitch does.

Cooper Hjerpe leans on his four-seam fastball (52% of pitches). His best pitch has been the sweeper, saving 2.3 bases per 100 thrown against league average.

Pitch mix & swing-and-miss

+13 bases better than a replacement arm this season

He allowed about 19 estimated bases, against a replacement arm's 32 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

He saved 2.8 bases against league average across 190 pitches, or 1.5 per 100 pitches.

Four-Seam Fastball
52%
90.4 mph · LHP median 93.5
24% whiffs · Lg median 21%
saved 1.1 per 1001.5 total
Sweeper
23%
77.5 mph · LHP median 81.2
—
saved 2.3 per 1001.3 total
Changeup
not charted
16%
81.0 mph · LHP median 85.1
—
—
Cutter
not charted
9%
86.2 mph · LHP median 88.0
—
—

His changeup and cutter aren't in the charts below, because too few of each were tracked this season.

How to read this chart
Each row is a pitch he throws at least 3% of the time, from pitch tracking in the regular season. The bar is how often he throws it, then its average velocity and its whiff rate, the share of swings that miss. Beside the velocity and the whiff rate is the median for that pitch, among pitchers of his hand for velocity and across the league for whiffs. More whiffs are better for a pitcher, while usage and velocity describe how he pitches. The Bases vs average bars score each pitch against a league-average pitch in the same count, and a bar to the left (saved) is better.

Mix by batter side

Compared with the league, his four-seam fastball tilts 27 points more toward lefties.

Four-Seam Fastball
61% vs LHH · LHP median 34%
42% vs RHH · LHP median 41%
How to read this chart
Each row shows how often he throws a pitch to left-handed hitters (LHH) and right-handed hitters (RHH), next to the median for pitchers of his hand (LHP median). Medians come from the 149 left-handed pitchers who throw that pitch at least 3% of the time. A mix is a plan, so a higher or lower share is neither better nor worse. Overall results by batter side are under Platoon splits.

By appearance

These charts follow his velocity, movement and mix from outing to outing.

These charts follow his velocity, movement and pitch mix one outing at a time, and each pitch keeps the same color in every chart. The velocity and movement charts also shade the middle of the league for scale. His changeup and cutter aren't in these charts, because too few of each were tracked this season.

Platoon splits

This section splits his results against lefties and righties.

Platoon splits (EB/PA allowed)

He handles lefty bats better than righty bats, by 0.038 EB/PA allowed.

50% probable range: +0.029 to +0.047

vs LHB28 PA0.390

vs LHB: shrunk estimate 0.390 EB/PA, 50% probable range 0.368 to 0.413, based on 28 plate appearances. Raw (unshrunk) rate: 0.452 EB/PA. League median vs LHB: 0.451 EB/PA.

vs RHB27 PA0.427

vs RHB: shrunk estimate 0.427 EB/PA, 50% probable range 0.406 to 0.450, based on 27 plate appearances. Raw (unshrunk) rate: 0.379 EB/PA. League median vs RHB: 0.435 EB/PA.

0.3580.3840.4100.4350.461
← betterworse →
Below league medianAbove50% probable rangeHis raw rateMiddle half of the league

His split is about typical for a lefty arm (median 0.038). He allows less than the league median against both sides, so even his weaker side is a strength.

How to read this chart
  • Each dot is his estimate against that side, with its 50% probable range as the bar. These are bases allowed, so lower is better.
  • The diamond is his raw rate, which small samples make noisy, so the simulator pulls the dot toward a more trustworthy value.
  • The dashed tick is the league median, and the shaded strip is the middle half of pitchers with 100 or more batters faced.
  • The two splits average back to his modeled overall EB/PA allowed, not the xEB/PA headline.
  • Tap or hover a mark for its number. LHB and RHB are left- and right-handed batters. More on the About page

Contact allowed

These cards show what hitters do when they make contact.

Batters go to the pull side off him most often, and that's also where they do the most damage.

Pull side and opposite field depend on which side each batter hits from, so this pools every hitter he faced.

Batted balls allowed

Every ball hit off Cooper Hjerpe this season is drawn where it landed.
hit · out
EBlowhigh
vs Ronny SimonSingle
104 mph · 18° · worth 1.4 bases
09/24 vs Pirates
vs James WoodDouble
88 mph · 12° · worth 1.3 bases
09/18 vs Nationals
vs Jacob YoungDouble
100 mph · 20° · worth 1.1 bases
09/18 vs Nationals
vs Munetaka MurakamiSingle
105 mph · 13° · worth 0.9 bases
09/12 vs White Sox
vs Ezequiel TovarOut
90 mph · 34° · worth 0.9 bases
09/06 vs Rockies
How to read this chart
Dot color is estimated bases (EB), what the contact was worth no matter what the defense did with it. Darker means more bases, 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

These are his biggest outings this season.

Best games

These are his best outings this season, ranked by bases saved against a replacement arm.