Herrera, Welinton
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 | 3.14 |
| ERA current pace | 0.00 |
| ERA rolling p50 | 3.01 |
| Observed weight | 4% |
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
2025 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 |
|---|---|---|---|---|
| FB | 63.0% | 17 | 115 | limited sample |
| CH | 22.2% | 6 | 101 | limited sample |
| SL | 14.8% | 4 | 76 | 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 | 31.0 | -- | -- |
| Batters Faced | 132 | -- | -- |
| K% | 22.3% | 0.1% to 19.6% | +/- 9.8% |
| BB% | 8.7% | 0.1% to 11.5% | +/- 5.7% |
| Whiff% | 23.6% | 2.3% to 27.2% | +/- 12.4% |
| HR/9 | 1.15 | 0.00 to 1.45 | +/- 0.72 |
| xwOBA Against | 0.285 | 0.001 to 0.315 | +/- 0.157 |
| Barrel% Allowed | 7.5% | 0.1% to 9.7% | +/- 4.8% |
| ERA | 3.68 | 0.00 to 4.81 | +/- 2.41 |
| FIP | 3.39 | 0.34 to 4.90 | +/- 2.28 |
| WHIP | 1.123 | 0.034 to 1.239 | +/- 0.602 |
0 career BF
| xwOBA | 0.004 |
| K% | 0.4% |
| BB% | 0.1% |
| Barrel | 0.1% |
1 career BF
| xwOBA | 0.005 |
| K% | 0.3% |
| BB% | 0.1% |
| Barrel | 0.1% |