Matthews, Zebby
Breaking-ball driven starter profile
Season percentile report
The headline weighs outcome stats (xwOBA, barrels); each bar averages its full strip group below. 100 = best in MLB.
percentile
Preseason / current pace / Bayesian update
Rolling bands shrink current-season signal toward the preseason prior until the sample earns more weight.
| ERA preseason | 4.41 |
| ERA current pace | 4.57 |
| ERA rolling p50 | 4.50 |
| Observed weight | 55% |
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
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 | 38.2% | 221 | 104 | qualified |
| SL | 20.0% | 116 | 102 | limited sample |
| CB | 14.7% | 85 | 100 | limited sample |
| CH | 12.8% | 74 | 108 | limited sample |
| FC | 11.4% | 66 | 104 | limited sample |
| SI | 2.9% | 17 | 103 | limited sample |
Renamed from the attempted Kirby Index after audit; true Kirby requires release-angle trajectory data.
Current-season signal
| ERA Δ | +0.15 |
| K% Δ | -0.047 |
| Sample | 71.0 IP |
positive regression
Point projection and range
| Metric | Point | Range | Half-width |
|---|---|---|---|
| Innings | 138.4 | -- | -- |
| Batters Faced | 624 | -- | -- |
| K% | 23.3% | 18.1% to 29.7% | +/- 5.8% |
| BB% | 6.9% | 4.5% to 8.6% | +/- 2.0% |
| Whiff% | 24.4% | 20.0% to 28.9% | +/- 4.5% |
| HR/9 | 1.32 | 0.82 to 2.37 | +/- 0.77 |
| xwOBA Against | 0.306 | 0.271 to 0.355 | +/- 0.042 |
| Barrel% Allowed | 8.0% | 4.5% to 13.0% | +/- 4.3% |
| ERA | 4.42 | 3.38 to 6.75 | +/- 1.69 |
| FIP | 3.78 | 2.66 to 5.55 | +/- 1.44 |
| WHIP | 1.281 | 1.099 to 1.648 | +/- 0.275 |
278 career BF
| xwOBA | 0.311 |
| K% | 20.5% |
| BB% | 6.5% |
| Barrel | 11.0% |
253 career BF
| xwOBA | 0.276 |
| K% | 21.0% |
| BB% | 4.9% |
| Barrel | 8.8% |