KPI Catalog & Methodology

Scouting & Analytic Rationale: Barrelling a breaking ball is rarer and more discriminating than hitting one hard. Median batter has 38 classified balls in play.

Scouting & Analytic Rationale: The best-populated damage cell on the hitter side. Median batter has 83 classified balls in play against the fastball family.

Scouting & Analytic Rationale: The split that decides a platoon start. Median batter has 40 classified balls in play against left-handers.

Scouting & Analytic Rationale: Offspeed damage is the cleanest signal a hitter can send about timing. Median batter has 22 measured balls in play against this family, so the floor keeps roughly the top half of the population.

Scouting & Analytic Rationale: Damage against the handedness a hitter sees most. Median batter has 100 classified balls in play.

Scouting & Analytic Rationale: A physical input rather than an outcome, so it degrades far more slowly than rate cells when a hitter is in a slump. Measured swing speed, not the competitive-swing leaderboard average.

Scouting & Analytic Rationale: Balls put in play divided by swings. Foul contact is excluded, so this is not the complement of whiff rate. Median batter has 111 swings.

Scouting & Analytic Rationale: The unconditioned version of the contact-quality cells, and the widest hitter population the catalog can rank. Median batter has 146 valid observations.

Scouting & Analytic Rationale: The breaking-ball counterpart, thinner but more discriminating because most hitters are worse here. Median batter has 37 valid observations.

Scouting & Analytic Rationale: Combines exit velocity and launch angle into one outcome-weighted number, so it separates productive contact from merely hard contact. Median batter has 82 valid observations.

Scouting & Analytic Rationale: A continuous mean rather than a proportion, so it carries information the rate cells round away. Takes a flat weak prior because the binomial shrinkage term does not apply.

Scouting & Analytic Rationale: Sinker-heavy starters live on this. Median batter has 83 classified balls in play against the fastball family.

Scouting & Analytic Rationale: The original worked example from the proposal. Median batter has 28 classified balls in play against the slider family. Ranking asks who pounds it into the ground most; that end is bad for the hitter, so favourable is the low end.

Scouting & Analytic Rationale: Separates hitters who merely make contact on breaking balls from those who damage them. Median batter has 38 measured exit velocities against this family.

Scouting & Analytic Rationale: Exit velocity against fastballs stabilises faster than any other contact-quality cell. Median batter has 83 measured exit velocities.

Scouting & Analytic Rationale: The outcome barrel rate is a leading indicator of. Holding both lets the catalog check whether the leading indicator is doing any work the outcome does not.

Scouting & Analytic Rationale: The outcome the whiff cells are supposed to add up to, kept as its own KPI so the arsenal-level cells can be checked against it. Median batter has 215 completed plate appearances.

Scouting & Analytic Rationale: Plate discipline is the half of offence the contact-quality cells cannot see at all. Median batter has 215 completed plate appearances.

Scouting & Analytic Rationale: Breaking-ball whiff is the split a starter with a plus slider attacks directly. Median batter has 111 swings against the family.

Scouting & Analytic Rationale: The deepest and best-populated cell available: median batter has 223 swings against the fastball family, so the interval here is genuinely tight.

Scouting & Analytic Rationale: Thinner than the right-handed split by construction, since most innings are thrown right-handed. Median batter has 111 swings.

Scouting & Analytic Rationale: Completes the three-family whiff picture so a starter's arsenal can be matched against the exact family each hitter misses. Median batter has 62 swings.

Scouting & Analytic Rationale: The platoon split the lineup card is actually built around. Median batter has 265 swings against right-handers.

Scouting & Analytic Rationale: The generalization ladder's level 6 asked exactly this and produced zero cells: 504,109 raw cells over 649,238 pitches, median one pitch, largest cell 56. Resolved here by backing off through handedness, pitch type, batter archetype and batter-by-pitcher archetype, so every pairing returns a number weighted by the data it actually has.

Scouting & Analytic Rationale: The same archetype pairing measured on swings rather than contact quality. Swings are the best-populated denominator available, so this is the deepest level the data supports most comfortably.

Scouting & Analytic Rationale: Pitcher-side control KPI with no pitch condition, so its cells are the largest in the seed set. Included to check that the scorecard can distinguish a well-measured KPI from a thin one.

Scouting & Analytic Rationale: The left-handed counterpart. Median pitcher has 42 classified balls in play.

Scouting & Analytic Rationale: Damage allowed split by hitter handedness, which is the form a lineup-construction decision actually takes. Median pitcher has 48 classified balls in play.

Scouting & Analytic Rationale: Outcome-weighted contact quality allowed, which is closer to runs than either barrel rate or hard-hit rate alone. Median pitcher has 88 valid observations.

Scouting & Analytic Rationale: The direct counterpart to the two hitter ground-ball cells, which is what makes a sinker-versus-groundball-hitter matchup expressible. Median pitcher has 89 classified balls in play.

Scouting & Analytic Rationale: A wider denominator than barrels allowed, so it stabilises sooner at the cost of being less extreme. Median pitcher has 89 measured exit velocities.

Scouting & Analytic Rationale: The outcome barrels allowed is a leading indicator of, kept separately so the pair can be compared. Median pitcher has 138 plate appearances faced.

Scouting & Analytic Rationale: A continuous mean over every pitch thrown, so it is pitch-mix dependent by construction: a heavy breaking-ball starter reads slower without being worse. Included as a physical input that moves slowly, not as a quality ranking.

Scouting & Analytic Rationale: The outcome the whiff cells should add up to on the pitcher side. Median pitcher has 138 completed plate appearances faced.

Scouting & Analytic Rationale: Command, which no contact-quality cell can see. Median pitcher has 138 completed plate appearances faced.

Scouting & Analytic Rationale: The single most stable pitcher skill available from pitch data. Median pitcher has 254 swings induced.

Scouting & Analytic Rationale: Pairs against batter_whiff_rate_vs_breaking. Median pitcher has 65 swings induced against the family.

Scouting & Analytic Rationale: Pairs directly against batter_whiff_rate_vs_fastball, which is the arsenal-versus-weakness comparison the catalog exists to make. Median pitcher has 146 swings induced.

Scouting & Analytic Rationale: The reverse-platoon half. Median pitcher has 117 swings induced against left-handed hitters.

Scouting & Analytic Rationale: The platoon half of pitcher whiff, which is what decides how a lineup is stacked against him. Median pitcher has 132 swings induced.