DataBaseball
2026
Geoff Hartlieb headshot

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, USA
MLB debut
May 18, 2019
Drafted
2015, round 37
College
Lindenwood
dbWAR
-.4
3 season(s)
IP
13.1
ERA
6.07
FIP
5.19
K/9
4.0
FIP−
124
100 = avg

Geoff Hartlieb is a relief pitcher for the Athletics. In 2026 he struck out 6 batters over 13.1 innings across 8 appearances, going 1-1. His ERA of 6.07 was 45.5% higher than the league average of 4.18. Stripping out defence, his 5.19 FIP suggests he pitched better than his ERA shows. He missed bats on 24.5% of swings (11.5% of every pitch he threw), walked 14.1% of the batters he faced and struck out 9.4%. His -0.1 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.

FIP5.19
K/94.0
WHIP1.95
WAR-.1

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 LHB31257053.280.387.400.3559.7%
vs RHB332710143.370.424.630.4389.1%

Pitch sequencing

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

ShowBatter
Four-seamSliderCutterSinker

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

Pitch arsenal

What he throws, how hard, and how often it misses in 2026.

Four-Seam Fastball35.9%7895.22,29235.9%11.8%
Slider30.4%6684.52,46039.4%37.9%
Cutter18.0%3991.42,46328.2%15.0%
Sinker15.7%3493.62,28238.2%36.8%
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.

Pitching

Standard and advanced, by season.

Trend
20268013.1110179696.075.191.954.06.1145124-0.1
2025403.1000885621.6013.344.2013.516.2519321-0.3
2024509.0000139749.004.391.897.04.02211080.0

Head to head

Put Geoff Hartlieb beside up to three others.

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Geoff Hartlieb
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.