Jerry Koosman vs Tom Seaver: Career Stats Comparison

Tom Seaver has the better career line of the two, leading 11 of the 12 statistical categories compared on this page. 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 came up during the 1960s, so the matchup is a direct one. Jerry Koosman compiled 222 wins and 2,556 strikeouts; Tom Seaver put up 311 wins and 3,640 strikeouts. The numbers below run them through identical career and rate-stat lenses.

Quick answer

  • 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.
  • Who pitched more innings? Tom Seaver, with 4,782 to Jerry Koosman's 3,839.
  • Who threw more shutouts? Tom Seaver, with 61 to Jerry Koosman's 33.
  • Who has the higher career Pitcher PIV? Tom Seaver, with 79,192 career Pitcher PIV to Jerry Koosman's 42,939.
Leads Tom Seaver 11 of 12 awarded categories
Pitcher PIV edge Tom Seaver +36,254
Read the verdict ↓

Jerry Koosman

Pitcher · 1967–1985
Wins
222
Losses
209
Strikeouts
2,556
ERA
3.36
WHIP
1.26
IP
3,839
View Jerry Koosman's full profile →

Tom Seaver

Pitcher · 1967–1986
Wins
311
Losses
205
Strikeouts
3,640
ERA
2.86
WHIP
1.12
IP
4,782
View Tom Seaver's full profile →

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. Totals where fewer is not an achievement -- losses, walks and hits allowed -- are left unmarked, because they track how long someone pitched rather than how well. Rate stats are not era-adjusted: compare them with the era in mind, or use the PIV card below, which is.

Jerry Koosman vs Tom Seaver: Career Stats Comparison — Career Stats Side-by-Side
Statistic Jerry Koosman Tom Seaver
Wins 222 Leads: 311
Losses 209 205
Games 612 Leads: 656
Games Started 527 Leads: 647
Complete Games 140 Leads: 231
Shutouts 33 Leads: 61
Saves Leads: 17 1
Strikeouts 2,556 Leads: 3,640
Walks 1,198 1,390
Hits Allowed 3,635 3,971
Home Runs Allowed 290 380
Innings Pitched 3,839 Leads: 4,782
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 — a gap driven primarily by per-season impact (3,600 vs 2,147 per year). PIV adjusts each season to league baselines, so it's the cleanest way to compare careers across eras.

Jerry Koosman
42,939
Career Pitcher PIV · 2,147 per season (20 seasons)
Tom Seaver
79,192
Career Pitcher PIV · 3,600 per season (22 seasons)

How PIV is calculated →

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)

19682.08 ERA19-12, 178 K in 263 IP
19692.28 ERA17-9, 180 K in 241 IP
19762.69 ERA21-10, 200 K in 247 IP

Tom Seaver — top 3 seasons by ERA (lower is better)

19711.76 ERA20-10, 289 K in 286 IP
19732.08 ERA19-10, 251 K in 290 IP
19682.20 ERA16-12, 205 K in 277 IP

Verdict

On the head-to-head card, Tom Seaver leads in wins, strikeouts, ERA, and WHIP, while Jerry Koosman owns no headline categories. That doesn't settle the era debate, but 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

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 11 of 12 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.

See These Players in Another Era