Jerry Koosman vs Jon Matlack: Career Stats Comparison
Jerry Koosman (1967–1985) and Jon Matlack (1971–1983) — breaking in during the 1960s and the 1970s respectively, so they pitched against very different hitting environments. Jerry Koosman compiled 222 wins and 2,556 strikeouts; Jon Matlack put up 125 wins and 1,516 strikeouts. The numbers below run them through identical career and rate-stat lenses.
Jerry Koosman
Jon Matlack
Career Stats Side-by-Side
Every cell below is a career total or career rate. Cells highlighted in green mark the player who leads that line. For pitchers, lower ERA, WHIP, and BB/9 lead; higher K/9 leads.
| Statistic | Jerry Koosman | Jon Matlack |
|---|---|---|
| Wins | 222 | 125 |
| Losses | 209 | 126 |
| Games | 612 | 361 |
| Games Started | 527 | 318 |
| Complete Games | 140 | 97 |
| Shutouts | 33 | 30 |
| Saves | 17 | 3 |
| Strikeouts | 2,556 | 1,516 |
| Walks | 1,198 | 638 |
| Hits Allowed | 3,635 | 2,276 |
| Home Runs Allowed | 290 | 161 |
| Innings Pitched | 3,839 | 2,363 |
| ERA | 3.36 | 3.18 |
| WHIP | 1.26 | 1.23 |
| K/9 | 5.99 | 5.77 |
| BB/9 | 2.81 | 2.43 |
PIV Comparison
By PIV (Player Impact Value), Jerry Koosman leads Jon Matlack 42,939 to 38,811 — a gap driven primarily by per-season impact (2,147 vs 2,985 per year). PIV adjusts each season to league baselines, so it's the cleanest way to compare careers across eras.
Peak Seasons
The best single seasons each player produced, ranked by ERA among qualified workloads (120+ innings).
Jerry Koosman — top 3 seasons by ERA (lower is better)
Jon Matlack — top 3 seasons by ERA (lower is better)
Verdict
On the head-to-head card, Jerry Koosman leads in wins, strikeouts, K/9, and innings pitched, while Jon Matlack owns ERA and WHIP. That doesn't settle the era debate, but on the raw scoreboard the edge goes to Jerry Koosman. PIV agrees: Jerry Koosman grades out higher across their careers. Click through to each profile for the full season-by-season breakdown.