← BackJack Kochanowicz
LAA · RHP · 2025
96.7 IP · 513 BF · 1,858 pitches · 2025 season
HIGH Descriptive — not a forecast
104
Stuff+
66th percentile
101
ABStuff+
49th percentile
98
Pitching+
14th percentile
14.0%
K%
10th percentile
10.5%
BB%
30th percentile
6.72
FIP
16th percentile
Grades describe this season's stuff and run prevention. They are not forecasts: on clean season pairs the model has not beaten naive persistence (RESULTS-MLB §13), so nothing here projects next season.
Percentile rankings
vs 2025 graded MLB pitchers · 96.7 IP · 513 BF · 1,858 pitches · 2025 season
Stuff
Stuff+104
66th percentile
ABStuff+101
49th percentile
Whiff%18.4%
22th percentile
CSW%29.3%
5th percentile
Results
Pitching+98
14th percentile
RV/100-1.42
21th percentile
FIP6.72
16th percentile
RA/94.00
60th percentile
GB%52.5%
87th percentile
Command
K%14.0%
10th percentile
BB%10.5%
30th percentile
K-BB%3.5%
12th percentile
Velo92.8
90th percentile
How to read these
Each row is his rank, 1 to 99, among all graded MLB pitchers this season; the tick is the median. Green is good for him, red bad, whatever the stat's direction (a low FIP ranks high). Grey circles are descriptive rates with no good direction, and n= in place of a rank means too few events to rank. Grades are descriptive, not forecasts.
Percentile rankings
Raw plate discipline · vs 2025 graded MLB pitchers · 96.7 IP · 513 BF · 1,858 pitches · 2025 season
Swing & miss
Z-Whf%9.9%
12th percentile
O-Whf%39.3%
40th percentile
Chase%27.0%
44th percentile
Z-Con%90.1%
12th percentile
O-Con%60.7%
40th percentile
SwStr%22.8%
5th percentile
PutAwy%13.0%
17th percentile
Approach
Zone%48.8%
35th percentile
Z-Swg%69.2%
69th percentile, descriptive, no good or bad direction
Swing%47.6%
53th percentile
CS%18.0%
25th percentile
F-Str%43.5%
14th percentile
How to read these
Raw rates with this season's descriptive ranks. Sample-adjusted (shrunk) rankings are not shown yet: the reliability constants behind them were measured on college data and are being re-measured on MLB. Until then a small sample here is a small sample — hover the leaderboard column for its event count.
ArsenalKey columns; every column is on the Arsenal tab
Movement Profile
SI-4.1/+2.0FF-1.9/+1.3SL-5.7/+1.7CH-4.2/+3.9SWring = slot expectation ±1σ/2σ · HB mirrored for LHP · descriptive
Release Traits
Height: 5.92 ft (±0.15)
Side: -1.89 ft (±0.20)
Extension: 6.42 ft
Season means; the ± is the SD across his pitches. Per-pitch release plots land in a later wave.
Batted Ball Against
Pitch
N_BIP
GB%
FB%
LD%
PU%
Avg EV
Avg LA
HrdHit%
SI
214
64.0
16.4
17.8
0.0
87.8
3.8
53.7
FF
54
20.4
37.0
29.6
0.0
85.5
31.3
51.9
CH
49
49.0
30.6
18.4
0.0
84.4
2.1
53.1
SL
38
47.4
26.3
21.1
0.0
85.9
8.9
28.9
SW
20
35.0
40.0
20.0
0.0
85.3
10.2
30.0
Every pitch type he threw, ordered by balls in play. Rows under 5 BIP are dimmed rather than dropped — a slider put in play twice is a fact about the slider.
Arsenal
Pitches
5
60th pct
Effective mix
4.0
67th pct
Separation
18.3
32nd pct
Shape scatter
3.4 in
79th pct
Velo range
13.2 mph
65th pct
SI · FF · SL · CH · SW
2025 season, 1,858 pitches; percentiles vs MLB pitchers with 100+ that season. A description of the arsenal, not a grade: none of these predicted next season beyond Pitching+ and his own prior year. For shape scatter a higher percentile is MORE scatter.
Location value
runs per 100 pitches vs league
Total
−0.19
16th percentile
Where he throws
−0.06
38th percentile
Which pitch there
−0.13
9th percentile
Heart28.8%
+148.26/100
Shadow41.3%
+125.76/100
Chase21.3%
−278.14/100
Waste8.5%
−488.14/100
What makes up the total
chase · SI10.3%−0.43
heart · SI13.2%+0.28
shadow · SI20.3%+0.25
waste · SI3.1%−0.24
chase · FB3.4%−0.17
11 other locations+0.12
Total−0.19
Pitcher-positive, centred on the 2025 league mean (+0.01 RV/100). Ranks are descriptive: the year-to-year reliability of this mix on MLB has not been measured yet, so no cell is verdict-coloured. His actual run value minus this mix — execution — is deliberately not shown.