Jansen, Kenley
Late-inning arm with usable miss-bat shape
Preseason / current pace / Bayesian update
Rolling bands shrink current-season signal toward the preseason prior until the sample earns more weight.
| ERA preseason | 3.84 |
| ERA current pace | 4.80 |
| ERA rolling p50 | 4.06 |
| Observed weight | 23% |
Actual percentile with projection tick
100th = best in MLB.
Stuff+ and arsenal context
Stuff+ appears when the current pitch-event scoring artifact includes this pitcher; Arsenal Decomposition remains descriptive support under Stuff+.
Arsenal optimization map
Pitch-shape context from this pitcher’s current arsenal snapshot. Hover a pitch to inspect usage, movement, and bat-missing context.
xwOBA allowed snapshot line
Live snapshot series; true 50/100 PA windows require PA-level logs
No Live State xwOBA snapshots are available for this player.
Aggregate zone heatmap
Aggregate zone metrics from seasonal Statcast leaderboards.
Usage mix, movement map, and Stuff+ composition
2026 pitch-level arsenal aggregates; current season takes over after 100 tracked pitches across at least 2 pitch types. Descriptive pitch-type Stuff+ composition. Not a promoted predictive metric.
| Pitch | Usage | Pitches | Stuff+ | Status |
|---|---|---|---|---|
| FC | 79.5% | 210 | 103 | qualified |
| SI | 10.2% | 27 | 102 | limited sample |
| SL | 10.2% | 27 | 101 | limited sample |
Renamed from the attempted Kirby Index after audit; true Kirby requires release-angle trajectory data.
Current-season signal
No Live State delta is available for this player yet.
Point projection and range
| Metric | Point | Range | Half-width |
|---|---|---|---|
| Innings | 39.1 | -- | -- |
| Batters Faced | 161 | -- | -- |
| K% | 22.5% | 17.2% to 31.3% | +/- 7.1% |
| BB% | 8.9% | 5.5% to 12.7% | +/- 3.6% |
| Whiff% | 22.4% | 17.8% to 27.9% | +/- 5.0% |
| HR/9 | 1.12 | 0.44 to 1.83 | +/- 0.70 |
| xwOBA Against | 0.316 | 0.256 to 0.373 | +/- 0.059 |
| Barrel% Allowed | 8.8% | 4.8% to 13.2% | +/- 4.2% |
| ERA | 3.81 | 1.98 to 5.95 | +/- 1.99 |
| FIP | 3.92 | 2.73 to 4.01 | +/- 0.64 |
| WHIP | 1.199 | 0.851 to 1.532 | +/- 0.341 |
1405 career BF
| xwOBA | 0.283 |
| K% | 21.7% |
| BB% | 9.4% |
| Barrel | 9.3% |
1454 career BF
| xwOBA | 0.261 |
| K% | 23.9% |
| BB% | 6.5% |
| Barrel | 8.7% |