Bert Blyleven vs Jerry Koosman: Career Stats Comparison
Bert Blyleven has the better career line of the two, leading 11 of the 12 statistical categories compared on this page. Bert Blyleven played 1970–1992 as a pitcher; Jerry Koosman played 1967–1985 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
Bert Blyleven (1970–1992) and Jerry Koosman (1967–1985) — breaking in during the 1970s and the 1960s respectively, so they pitched against very different hitting environments. Bert Blyleven compiled 287 wins and 3,701 strikeouts; Jerry Koosman put up 222 wins and 2,556 strikeouts. The numbers below run them through identical career and rate-stat lenses.
Quick answer
- Who had the better ERA? Bert Blyleven, with 3.31 to Jerry Koosman's 3.36.
- Who won more games? Bert Blyleven, with 287 to Jerry Koosman's 222.
- Who recorded more strikeouts? Bert Blyleven, with 3,701 to Jerry Koosman's 2,556.
- Who had the better WHIP? Bert Blyleven, with 1.20 to Jerry Koosman's 1.26.
- Who pitched more innings? Bert Blyleven, with 4,970 to Jerry Koosman's 3,839.
- Who threw more shutouts? Bert Blyleven, with 60 to Jerry Koosman's 33.
- Who has the higher career Pitcher PIV? Bert Blyleven, with 74,910 career Pitcher PIV to Jerry Koosman's 42,939.
Bert Blyleven
Jerry Koosman
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.
| Statistic | Bert Blyleven | Jerry Koosman |
|---|---|---|
| Wins | Leads: 287 | 222 |
| Losses | 250 | 209 |
| Games | Leads: 692 | 612 |
| Games Started | Leads: 685 | 527 |
| Complete Games | Leads: 242 | 140 |
| Shutouts | Leads: 60 | 33 |
| Saves | 0 | Leads: 17 |
| Strikeouts | Leads: 3,701 | 2,556 |
| Walks | 1,322 | 1,198 |
| Hits Allowed | 4,632 | 3,635 |
| Home Runs Allowed | 430 | 290 |
| Innings Pitched | Leads: 4,970 | 3,839 |
| ERA | Leads: 3.31 | 3.36 |
| WHIP | Leads: 1.20 | 1.26 |
| K/9 | Leads: 6.70 | 5.99 |
| BB/9 | Leads: 2.39 | 2.81 |
PIV Comparison
By PIV (Player Impact Value), Bert Blyleven outpaces Jerry Koosman 74,910 to 42,939 — a gap driven primarily by per-season impact (3,121 vs 2,147 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).
Bert Blyleven — top 3 seasons by ERA (lower is better)
Jerry Koosman — top 3 seasons by ERA (lower is better)
Verdict
On the head-to-head card, Bert Blyleven 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 Bert Blyleven. PIV agrees: Bert Blyleven grades out higher across their careers. Click through to each profile for the full season-by-season breakdown.
Related Matchups
Bert Blyleven vs Jerry Koosman: Frequently Asked Questions
- Who was better, Bert Blyleven or Jerry Koosman?
- By the career statistics compared on this page, Bert Blyleven leads Jerry Koosman in 11 of 12 categories.
- Who had the better ERA?
- Bert Blyleven, with 3.31 to Jerry Koosman's 3.36.
- Who won more games?
- Bert Blyleven, with 287 to Jerry Koosman's 222.
- Who recorded more strikeouts?
- Bert Blyleven, with 3,701 to Jerry Koosman's 2,556.
- Who had the better WHIP?
- Bert Blyleven, with 1.20 to Jerry Koosman's 1.26.