Jim Kaat vs Warren Spahn: Career Stats Comparison
Warren Spahn has the better career line of the two, leading 9 of the 12 scored categories on this page (4 further counting totals are shown but not scored). Jim Kaat played 1959–1983 as a pitcher; Warren Spahn played 1942–1965 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
Jim Kaat (1959–1983) and Warren Spahn (1942–1965) — breaking in during the 1950s and the 1940s respectively, so they pitched against very different hitting environments. Jim Kaat finished with 283 wins and 2,461 strikeouts; Warren Spahn finished with 363 wins and 2,583 strikeouts. The numbers below run them through identical career and rate-stat lenses.
Quick answer
- Who had the better ERA? Warren Spahn, with 3.09 to Jim Kaat's 3.45.
- Who won more games? Warren Spahn, with 363 to Jim Kaat's 283.
- Who recorded more strikeouts? Warren Spahn, with 2,583 to Jim Kaat's 2,461.
- Who had the better WHIP? Warren Spahn, with 1.19 to Jim Kaat's 1.26.
- Who pitched more innings? Warren Spahn, with 5,243.2 to Jim Kaat's 4,530.1.
- Who threw more shutouts? Warren Spahn, with 63 to Jim Kaat's 31.
- Who has the higher career Pitcher PIV? Warren Spahn, with 63,558 career Pitcher PIV to Jim Kaat's 26,792.
Jim Kaat
Warren Spahn
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. 12 of the 16 lines below are scored; the other 4 are counting totals on which fewer is not an achievement, so no one is awarded them. 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, and the 1950s and the 1940s were different run environments, so read them against their eras, or use the PIV card below, which is adjusted.
| Statistic | Jim Kaat | Warren Spahn |
|---|---|---|
| Wins | 283 | Leads: 363 |
| Losses not scored | 237 | 245 |
| Games | Leads: 898 | 750 |
| Games Started | 625 | Leads: 665 |
| Complete Games | 180 | Leads: 382 |
| Shutouts | 31 | Leads: 63 |
| Saves | 18 | Leads: 29 |
| Strikeouts | 2,461 | Leads: 2,583 |
| Walks not scored | 1,083 | 1,434 |
| Hits Allowed not scored | 4,620 | 4,830 |
| Home Runs Allowed not scored | 395 | 434 |
| Innings Pitched | 4,530.1 | Leads: 5,243.2 |
| ERA | 3.45 | Leads: 3.09 |
| WHIP | 1.26 | Leads: 1.19 |
| K/9 | Leads: 4.89 | 4.43 |
| BB/9 | Leads: 2.15 | 2.46 |
PIV Comparison through 2025
By PIV (Player Impact Value), Warren Spahn outpaces Jim Kaat 63,558 to 26,792 — driven by per-season impact — 2,889 PIV per season to 957 — rather than by longevity, since Warren Spahn played 22 seasons to Jim Kaat's 28. PIV adjusts each season to league baselines, so it's the cleanest way to compare careers across eras.
PIV is computed through the 2025 season. The career totals on this page include 2026 to date, so PIV does not yet reflect the 2026 season.
Peak Seasons
The best single seasons each player produced, ranked by ERA among qualified workloads (120+ innings).
Jim Kaat — top 3 seasons by ERA (lower is better)
Warren Spahn — top 3 seasons by ERA (lower is better)
Verdict
On the head-to-head card, Warren Spahn leads in wins, strikeouts, ERA, and WHIP, while Jim Kaat owns K/9. That doesn't settle the era debate, but on the raw scoreboard the edge goes to Warren Spahn. PIV agrees: Warren Spahn grades out higher across their careers. Click through to each profile for the full season-by-season breakdown.
Related Matchups
How the Jim Kaat and Warren Spahn careers compare
Jim Kaat and Warren Spahn were active at the same time between 1959 and 1965. With 898 games against 750 across 28 and 22 PIV seasons, neither player's totals owe much to extra seasons. The green cells for Jim Kaat are games (898 to 750), strikeouts per nine (4.89 to 4.43), and walks per nine (2.15 to 2.46). By rate, Jim Kaat struck out 4.89 and walked 2.15 per nine innings; Warren Spahn struck out 4.43 and walked 2.46. Jim Kaat split time between starting and relief (625 starts in 898 games), while Warren Spahn was mainly a starter (665 starts in 750 games).
Jim Kaat vs Warren Spahn: Frequently Asked Questions
- Who was better, Jim Kaat or Warren Spahn?
- By the career statistics compared on this page, Warren Spahn leads Jim Kaat in 9 of the 12 scored categories.
- Who had the better ERA?
- Warren Spahn, with 3.09 to Jim Kaat's 3.45.
- Who won more games?
- Warren Spahn, with 363 to Jim Kaat's 283.
- Who recorded more strikeouts?
- Warren Spahn, with 2,583 to Jim Kaat's 2,461.
- Who had the better WHIP?
- Warren Spahn, with 1.19 to Jim Kaat's 1.26.