Kenley Jansen vs Gregg Olson: Career Stats Comparison
Kenley Jansen 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). Kenley Jansen has played 2010–present as a pitcher; Gregg Olson played 1988–2001 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
Kenley Jansen (2010–present) and Gregg Olson (1988–2001) — breaking in during the 2010s and the 1980s respectively, so they pitched against very different hitting environments. Kenley Jansen has 58 wins and 1,329 strikeouts through October 12, 2026; Gregg Olson finished with 40 wins and 588 strikeouts. The numbers below run them through identical career and rate-stat lenses.
Quick answer
- Who had the better ERA? Kenley Jansen, with 2.60 to Gregg Olson's 3.46.
- Who won more games? Kenley Jansen, with 58 to Gregg Olson's 40.
- Who recorded more strikeouts? Kenley Jansen, with 1,329 to Gregg Olson's 588.
- Who had the better WHIP? Kenley Jansen, with 0.97 to Gregg Olson's 1.38.
- Who pitched more innings? Kenley Jansen, with 972.1 to Gregg Olson's 672.0.
- Who threw more shutouts? Neither — both are at 0.
- Who has the higher career Pitcher PIV? Kenley Jansen, with 34,863 career Pitcher PIV to Gregg Olson's 10,029.
Kenley Jansen
Gregg Olson
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 2010s and the 1980s were different run environments, so read them against their eras, or use the PIV card below, which is adjusted.
Kenley Jansen is still active — his totals below are current through October 12, 2026.
| Statistic | Kenley Jansen | Gregg Olson |
|---|---|---|
| Wins | Leads: 58 | 40 |
| Losses not scored | 46 | 39 |
| Games | Leads: 983 | 622 |
| Games Started | 0 | 0 |
| Complete Games | 0 | 0 |
| Shutouts | 0 | 0 |
| Saves | Leads: 498 | 217 |
| Strikeouts | Leads: 1,329 | 588 |
| Walks not scored | 305 | 330 |
| Hits Allowed not scored | 634 | 598 |
| Home Runs Allowed not scored | 95 | 46 |
| Innings Pitched | Leads: 972.1 | 672.0 |
| ERA | Leads: 2.60 | 3.46 |
| WHIP | Leads: 0.97 | 1.38 |
| K/9 | Leads: 12.30 | 7.88 |
| BB/9 | Leads: 2.82 | 4.42 |
PIV Comparison through 2025
By PIV (Player Impact Value), Kenley Jansen outpaces Gregg Olson 34,863 to 10,029 — driven by per-season impact — 2,179 PIV per season to 590 — rather than by longevity, since Kenley Jansen played 16 seasons to Gregg Olson's 17. 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).
Kenley Jansen
No seasons meet the qualifying workload, so there is no peak-season list to show.
Gregg Olson
No seasons meet the qualifying workload, so there is no peak-season list to show.
Verdict
On the head-to-head card, Kenley Jansen leads in wins, strikeouts, ERA, and WHIP, while Gregg Olson owns no headline categories. That doesn't settle the era debate, but on the raw scoreboard the edge goes to Kenley Jansen. PIV agrees: Kenley Jansen grades out higher across their careers. Click through to each profile for the full season-by-season breakdown.
Related Matchups
How the Kenley Jansen and Gregg Olson careers compare
Gregg Olson (1988–2001) was finished before Kenley Jansen (2010–present) arrived, so they never shared a league. Kenley Jansen has the far longer record, 983 games against 622 across 16 and 17 PIV seasons, which inflates every career total. Kenley Jansen leads every scored row of the table. By rate, Kenley Jansen struck out 12.30 and walked 2.82 per nine innings; Gregg Olson struck out 7.88 and walked 4.42. Kenley Jansen worked mostly in relief (0 starts in 983 games, 498 saves), and Gregg Olson worked mostly in relief (0 starts in 622 games, 217 saves). In WHIP, Kenley Jansen's 0.97 beats Gregg Olson's 1.38. Because Kenley Jansen is still playing, the totals above will keep moving through the season.
Kenley Jansen vs Gregg Olson: Frequently Asked Questions
- Who was better, Kenley Jansen or Gregg Olson?
- By the career statistics compared on this page, Kenley Jansen leads Gregg Olson in 9 of the 12 scored categories.
- Who had the better ERA?
- Kenley Jansen, with 2.60 to Gregg Olson's 3.46.
- Who won more games?
- Kenley Jansen, with 58 to Gregg Olson's 40.
- Who recorded more strikeouts?
- Kenley Jansen, with 1,329 to Gregg Olson's 588.
- Who had the better WHIP?
- Kenley Jansen, with 0.97 to Gregg Olson's 1.38.