Kenley Jansen vs Scott Williamson: 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; Scott Williamson played 1999–2007 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 Scott Williamson (1999–2007) — breaking in during the 2010s and the 1990s respectively, so they pitched against very different hitting environments. Kenley Jansen has 58 wins and 1,329 strikeouts through October 12, 2026; Scott Williamson finished with 28 wins and 510 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 Scott Williamson's 3.36.
- Who won more games? Kenley Jansen, with 58 to Scott Williamson's 28.
- Who recorded more strikeouts? Kenley Jansen, with 1,329 to Scott Williamson's 510.
- Who had the better WHIP? Kenley Jansen, with 0.97 to Scott Williamson's 1.30.
- Who pitched more innings? Kenley Jansen, with 972.1 to Scott Williamson's 439.1.
- 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 Scott Williamson's 11,282.
Kenley Jansen
Scott Williamson
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 1990s 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 | Scott Williamson |
|---|---|---|
| Wins | Leads: 58 | 28 |
| Losses not scored | 46 | 28 |
| Games | Leads: 983 | 344 |
| Games Started | 0 | Leads: 10 |
| Complete Games | 0 | 0 |
| Shutouts | 0 | 0 |
| Saves | Leads: 498 | 55 |
| Strikeouts | Leads: 1,329 | 510 |
| Walks not scored | 305 | 244 |
| Hits Allowed not scored | 634 | 326 |
| Home Runs Allowed not scored | 95 | 35 |
| Innings Pitched | Leads: 972.1 | 439.1 |
| ERA | Leads: 2.60 | 3.36 |
| WHIP | Leads: 0.97 | 1.30 |
| K/9 | Leads: 12.30 | 10.45 |
| BB/9 | Leads: 2.82 | 5.00 |
PIV Comparison through 2025
By PIV (Player Impact Value), Kenley Jansen outpaces Scott Williamson 34,863 to 11,282 — driven by both sides of the ledger: 2,179 PIV per season to 1,026, across 16 seasons to 11. 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.
Scott Williamson
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 Scott Williamson 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 Scott Williamson careers compare
No season is shared: Scott Williamson played 1999–2007, Kenley Jansen 2010–present. The table compares 983 games of Kenley Jansen with 344 of Scott Williamson across 16 and 11 PIV seasons; totals favor the longer career by default. Scott Williamson's edges on the table are starts (10 to 0). The per-nine rows read 12.30 strikeouts and 2.82 walks for Kenley Jansen, 10.45 and 5.00 for Scott Williamson. Both had the same role: Kenley Jansen worked mostly in relief (0 starts in 983 games, 498 saves); Scott Williamson worked mostly in relief (10 starts in 344 games, 55 saves). In WHIP, Kenley Jansen's 0.97 beats Scott Williamson's 1.30. Because Kenley Jansen is still playing, the totals above will keep moving through the season.
Kenley Jansen vs Scott Williamson: Frequently Asked Questions
- Who was better, Kenley Jansen or Scott Williamson?
- By the career statistics compared on this page, Kenley Jansen leads Scott Williamson in 9 of the 12 scored categories.
- Who had the better ERA?
- Kenley Jansen, with 2.60 to Scott Williamson's 3.36.
- Who won more games?
- Kenley Jansen, with 58 to Scott Williamson's 28.
- Who recorded more strikeouts?
- Kenley Jansen, with 1,329 to Scott Williamson's 510.
- Who had the better WHIP?
- Kenley Jansen, with 0.97 to Scott Williamson's 1.30.