MLB / Pitch matchup context

Pitch Mix Concentration

Explore league pitch-type concentration alongside the counts in which each pitch type appears.

Derived analysis19 published rows7 fieldsSource dates and observation windows below

Source context

Snapshot dates, source coverage, and selected row windows are reported separately because contributing modules do not share one window.

statcast_showcaseSnapshot date: not published; local 2025 pullSource coverage: not recordedRow window: not recordedFeeds: Pitch share, HHI contribution, Pitches
atlas_mlb_pitch_manifestSnapshot date: 2025-09-28Source coverage: not recordedRow window: not recordedFeeds: 0-0 share within pitch type, Two-strike share within pitch type, Peak count share within pitch type, Published count states (of 12)

Published measurements

Choose a measurement

MeasurementPopulationOrder

19 matching rows; 19 contain hhi contribution.

CSV includes 19 matching rows, all fields, and source context; missing measurements stay blank. Published source dates and row provenance are included when available; structured provenance uses JSON cells.

Measured rows: 19 / 190 unavailable
Median: 0.000024Middle ranked value
Middle 50%: 0.000001 to 0.005725th to 75th percentile
Observed range: 0 to 0.101Minimum to maximum

Summaries describe the filtered rows with equal row weight. Row counts are not independent game or event counts.

Measurement availability7 / 7 fields have values

Reference population: All published groups. 19 rows published.

Text search does not change this reference population.

Availability describes published values only. It does not establish data quality or independent game counts, and measurement windows can differ.

0HHI contribution0.101

Showing 16 of 19 matching numeric rows. Open a row to inspect all its fields. Rankings apply only to the published subset.

01 / Interpretation

What this measures

Pitch share and HHI describe concentration across pitch types. Count shares describe where a given pitch type appears: a 30% two-strike share means 30% of that type's pitches had two strikes before the pitch. It does not mean that type was chosen for 30% of all two-strike pitches. Read raw support and missing count coverage before comparing types; these frequencies do not measure effectiveness.

02 / Calculation

league_share = published pct / 100; HHI = sum(league_share^2); row contribution = league_share^2. first_pitch_share = count_state_pct[0-0] / 100. two_strike_share = sum(count_state_pct[0-2, 1-2, 2-2, 3-2]) / 100, requiring all four cells. peak_count_share = max(all 12 published count_state_pct cells) / 100; tied peak counts are all retained. count_states = number of valid explicitly published count cells, not event counts. All count shares use pitches of that type as their denominator.

Use the table to inspect available fields and the source JSON to trace the formula inputs. CSV percentage values are stored as fractions.

03 / Population & limits

All 19 published pitch-type rows from the local 2025 Statcast pull (693,037 pitches). Both public sources match on every pitch code, pitch count and rounded overall share.

League aggregates mix pitchers, roles and dates; they do not describe an individual pitcher or a matchup forecast. Count shares divide by pitches of that type, not all pitches in that count. Missing count keys are unavailable, not zero; exact event totals cannot be reconstructed from rounded percentages. Small categories carry high sampling noise and are shown for completeness, not comparison. UNK includes missing classifications. Matching totals do not establish matching observation dates: Statcast publishes only a local 2025 pull, while the Atlas separately publishes its as-of date.

04 / Source & method references

Published source JSON Statcast CSV documentation: pitch_type, balls and strikes Published CourtVision MLB pitch Atlas

References explain ingredients and prior methods. They do not validate this derived analysis or establish its originality.