DataBaseball
2026
Shun Yamaguchi headshot

Pitcher · 2020

Shun Yamaguchi

Age
33
B/T
R/R
Height
6' 2"
Weight
225 lb
Born
July 11, 1987 in Nakatsu, Japan
MLB debut
July 26, 2020
dbWAR
-.4
1 season(s)
IP
25.2
ERA
8.06
FIP
6.43
K/9
9.1
FIP−
144
100 = avg

Shun Yamaguchi is a relief pitcher for the Toronto Blue Jays. In 2020 he struck out 26 batters over 25.2 innings across 17 appearances, going 2-4. His ERA of 8.06 was 81.1% higher than the league average of 4.45 — the worst on his team, and 314th of 323 among MLB pitchers with 20+ innings. Stripping out defence, his 6.43 FIP suggests he pitched better than his ERA shows. He missed bats on 28.0% of swings (13.7% of every pitch he threw), walked 14.2% of the batters he faced and struck out 21.7%. 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, 2020.

FIP6.43
K/99.1
WHIP1.75
WAR-.4

Pitching

Standard and advanced, by season.

Trend
202017025.2240282326178.066.431.759.16.0181144-0.4

Platoon splits

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

Opponent batting by the side the hitter bats from, 2020. Counted from play-by-play, so totals can differ from the box-score season line by a plate appearance or two.
SplitPAABHHRBBSOAVGOBPSLGwOBAK%
vs LHB504210369.238.340.595.38618.0%
vs RHB70571831117.316.429.526.41324.3%

Pitch sequencing

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

ShowBatter
Four-seamSplitterSliderCurveball

Select a count to see exactly what Shun Yamaguchi throws in it.

Pitch arsenal

What he throws, how hard, and how often it misses in 2020.

Four-Seam Fastball40.8%20590.82,12950.7%25.3%
Splitter39.4%19884.81,26142.4%27.7%
Slider17.1%8681.62,29045.3%35.1%
Curveball2.4%1271.32,4798.3%50.0%
Shun Yamaguchi'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.

Head to head

Put Shun Yamaguchi beside up to three others.

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Shun Yamaguchi

Similar players

Nearest 2020 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.