Jerry Koosman vs Tom Seaver: Career Stats Comparison
Tom Seaver has the better career line of the two, leading 8 of the 8 scored categories on this page (8 further counting totals are shown but not scored). Jerry Koosman played 1967–1985 as a pitcher; Tom Seaver played 1967–1986 as a pitcher.
- ERA (Earned Run Average):
- Earned runs allowed per nine innings pitched: (ER × 9) ÷ IP. The primary measure of pitching effectiveness.
- W (Wins):
- Games credited to a pitcher whose team took a lead it never surrendered while he was the pitcher of record.
- SO (Strikeouts):
- For a batter, times retired on a third strike; for a pitcher, batters retired on a third strike.
- WHIP (Walks and Hits per Inning Pitched):
- Baserunners allowed per inning: (BB + H) ÷ IP. Under 1.00 is elite.
Data updated
Jerry Koosman (1967–1985) and Tom Seaver (1967–1986) — both debuted in the 1960s. Jerry Koosman finished with 222 wins and 2,556 strikeouts; Tom Seaver finished with 311 wins and 3,640 strikeouts. The table below sets out their careers line by line.
Quick answer
- Who leads the career comparison? Tom Seaver, in 8 of the 8 scored categories.
- Who had the better ERA? Tom Seaver, with 2.86 to Jerry Koosman's 3.36.
- Who won more games? Tom Seaver, with 311 to Jerry Koosman's 222.
- Who recorded more strikeouts? Tom Seaver, with 3,640 to Jerry Koosman's 2,556.
- Who had the better WHIP? Tom Seaver, with 1.12 to Jerry Koosman's 1.26.
- How many innings did each pitch? Jerry Koosman 3,839.1, Tom Seaver 4,782.2.
- Who threw more shutouts? Tom Seaver, with 61 to Jerry Koosman's 33.
Jerry Koosman
Tom Seaver
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. Lower ERA, WHIP and BB/9 lead; higher K/9 leads. 8 of the 16 lines below are scored; the other 8 are shown but not scored. Games, starts and innings measure playing time, and losses, walks and hits allowed track how long someone pitched, so they are left unmarked, as is any line where both players are at zero. Rate stats are not era-adjusted, so read them against the run environment each player worked in, or use the PIV card below, which is adjusted.
| Statistic | Jerry Koosman | Tom Seaver |
|---|---|---|
| Wins | 222 | Leads: 311 |
| Losses not scored | 209 | 205 |
| Games not scored | 612 | 656 |
| Games Started not scored | 527 | 647 |
| Complete Games | 140 | Leads: 231 |
| Shutouts | 33 | Leads: 61 |
| Saves not scored | 17 | 1 |
| Strikeouts | 2,556 | Leads: 3,640 |
| Walks not scored | 1,198 | 1,390 |
| Hits Allowed not scored | 3,635 | 3,971 |
| Home Runs Allowed not scored | 290 | 380 |
| Innings Pitched not scored | 3,839.1 | 4,782.2 |
| ERA | 3.36 | Leads: 2.86 |
| WHIP | 1.26 | Leads: 1.12 |
| K/9 | 5.99 | Leads: 6.85 |
| BB/9 | 2.81 | Leads: 2.62 |
PIV Comparison
By PIV (Player Impact Value), Tom Seaver outpaces Jerry Koosman 79,192 to 42,939 — driven by both sides of the ledger: 3,960 PIV per season to 2,260, across 20 seasons to 19. 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)
Tom Seaver — top 3 seasons by ERA (lower is better)
Verdict
Tom Seaver leads 8 of the 8 scored categories on the head-to-head card: wins, complete games, shutouts, strikeouts, and others. Jerry Koosman leads 0: no scored category. On the raw scoreboard the edge goes to Tom Seaver. PIV agrees: Tom Seaver grades out higher across their careers. Click through to each profile for the full season-by-season breakdown.
Related Matchups
How the Jerry Koosman and Tom Seaver careers compare
The careers of Jerry Koosman (1967–1985) and Tom Seaver (1967–1986) overlapped from 1967 to 1985, so for those seasons they faced the same league conditions. The two careers are close in length, 612 games for Jerry Koosman and 656 for Tom Seaver across 19 and 20 PIV seasons, so the totals compare on fairly even terms. Tom Seaver leads every scored row of the table. By rate, Jerry Koosman struck out 5.99 and walked 2.81 per nine innings; Tom Seaver struck out 6.85 and walked 2.62. Jerry Koosman was mainly a starter (527 starts in 612 games), and Tom Seaver was mainly a starter (647 starts in 656 games).
Jerry Koosman vs Tom Seaver: Frequently Asked Questions
- Who was better, Jerry Koosman or Tom Seaver?
- By the career statistics compared on this page, Tom Seaver leads Jerry Koosman in 8 of the 8 scored categories.
- Who had the better ERA?
- Tom Seaver, with 2.86 to Jerry Koosman's 3.36.
- Who won more games?
- Tom Seaver, with 311 to Jerry Koosman's 222.
- Who recorded more strikeouts?
- Tom Seaver, with 3,640 to Jerry Koosman's 2,556.
- Who had the better WHIP?
- Tom Seaver, with 1.12 to Jerry Koosman's 1.26.