DataBaseball
2026
Geoff Hartlieb headshot

Players · H · Pitcher · 2026

Geoff Hartlieb

Age
33
B/T
R/R
Height
6' 5"
Weight
240 lb
Number
#31
Born
December 9, 1993 in Highland, IL, United States
MLB debut
May 18, 2019
Drafted
2015, round 37
College
Lindenwood
dbWAR
-.3
7 season(s)
IP
26.1
ERA
4.78
FIP
3.60
K/9
7.2
FIP−
86
100 = avg

Geoff Hartlieb is a relief pitcher for the Athletics. In 2026 he struck out 21 batters over 26.1 innings across 17 appearances, going 2-1. His ERA of 4.78 is 14.5% higher than the league average of 4.18 — 9th of 18 on his team, and 376th of 538 among MLB pitchers with 20+ innings. Stripping out defence, his 3.60 FIP suggests he pitched better than his ERA shows. He missed bats on 27.1% of swings (13.2% of every pitch he threw), walked 11.2% of the batters he faced and struck out 18.1%. His 0.4 dbWAR is built from that FIP rather than runs allowed, so it credits him for what he controls and not for the defence behind him.

League context

Percentile among qualified pitchers, 2026.

FIP3.60
K/97.2
WHIP1.52
WAR.4

WAR by season

0.40.0-0.319202123242526

Pitching

Standard and advanced, by season.

Trend
2026ATH17026.1210271421134.783.601.527.24.4115860.4
2025DET/NYY403.1000885621.6013.344.2013.516.2519321-0.3
2024COL509.0000139749.004.391.897.04.02211080.0
2023MIA204.000021332.257.261.256.86.852167-0.1
2021PIT/NYM709.0000101191111.005.842.339.011.0258137-0.1
2020PIT21022.110016919193.635.031.577.77.7811130.0
2019PIT29035.0010523538189.005.562.009.84.6200123-0.2

Platoon splits

How left- and right-handed hitters fare against him.

Opponent batting by the side the hitter bats from, 2026. Counted from play-by-play, so totals can differ from the box-score season line by a plate appearance or two.
SplitPAABHHRBBSOAVGOBPSLGwOBAK%
vs LHB5344120711.273.377.364.34020.8%
vs RHB6355151610.273.333.400.32315.9%

Pitch sequencing

What Geoff Hartlieb throws in each count, and what he follows each pitch with. Select any cell for the breakdown.

ShowBatter
SliderFour-seamSinkerCutter

Select a count to see exactly what Geoff Hartlieb throws in it.

Pitch arsenal

What he throws, how hard, how often it misses, and what hitters do with it.

Slider34.6%14184.72,46848.9%44.3%34.176.510
Four-Seam Fastball31.9%13095.42,31540.8%14.0%27.259.766
Cutter16.9%6991.52,45037.7%11.4%17.294.762
Sinker16.7%6893.92,30438.2%29.7%21.4291.026
Geoff Hartlieb's arsenal by usage. Velocity is average release speed in mph, spin in rpm, and whiff rate is misses per swing — the cleanest single measure of whether a pitch beats hitters. BAA and OPS are what hitters did against each pitch, credited to the one that ended the plate appearance, and are left blank under 15 at-bats.

Head to head

Put Geoff Hartlieb beside up to three others.

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Geoff Hartlieb

Similar players

Nearest 2026 seasons by command, run prevention and role, on rate statistics rather than totals.

How these are computed

wOBA uses linear weights measured from this season's own play-by-play rather than published constants, and wRC+ is park-adjusted against that same league. dbWAR is our own open implementation — not fWAR or bWAR — and the full derivation, including its simplifications, is on the methodology page.