Halvorsen, Seth
Run-prevention profile built on workable command
Preseason / current pace / Bayesian update
Rolling bands shrink current-season signal toward the preseason prior until the sample earns more weight.
| ERA preseason | 3.67 |
| ERA current pace | 3.86 |
| ERA rolling p50 | 3.71 |
| Observed weight | 21% |
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 |
|---|---|---|---|---|
| FB | 67.7% | 109 | 99 | limited sample |
| SL | 32.3% | 52 | 99 | 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 | 34.4 | -- | -- |
| Batters Faced | 148 | -- | -- |
| K% | 23.4% | 16.6% to 33.0% | +/- 8.2% |
| BB% | 10.6% | 7.0% to 14.9% | +/- 4.0% |
| Whiff% | 27.0% | 22.0% to 34.7% | +/- 6.3% |
| HR/9 | 1.12 | 0.59 to 2.26 | +/- 0.83 |
| xwOBA Against | 0.318 | 0.251 to 0.363 | +/- 0.056 |
| Barrel% Allowed | 7.8% | 3.5% to 11.9% | +/- 4.2% |
| ERA | 4.44 | 2.28 to 6.59 | +/- 2.16 |
| FIP | 4.12 | 2.89 to 5.25 | +/- 1.18 |
| WHIP | 1.417 | 1.030 to 1.820 | +/- 0.395 |
124 career BF
| xwOBA | 0.278 |
| K% | 19.5% |
| BB% | 10.8% |
| Barrel | 8.0% |
112 career BF
| xwOBA | 0.260 |
| K% | 23.1% |
| BB% | 8.1% |
| Barrel | 7.4% |