Glossary

(0.69·uBB + 0.72·HBP + 0.89·1B + 1.27·2B + 1.62·3B + 2.10·HR) ÷ (AB + BB − IBB + SF + HBP), × wOBA scale

On-base percentage treats a walk and a home run as the same event. wOBA weights each outcome by the runs it actually produces. The scale factor is solved so league wOBA equals league OBP, which puts the number on a familiar range without importing another league's run values.

100 × (wRAA/PA + lgR/PA) ÷ (lgR/PA)

Runs created per plate appearance against the league, where 100 is average and 150 means half again as productive as a league-average hitter.

LimitNo park factor. The KBO does not publish runs by venue, so a Sajik hitter and a Jamsil hitter are compared as though the parks were identical.

SLG − AVG

Extra bases per at-bat. It separates power from the ability to make contact, which slugging alone conflates.

(H − HR) ÷ (AB − SO − HR + SF)

How often a ball put in play becomes a hit. Well above .340 usually means good fortune rather than a new skill; a hitter with genuine speed or hard contact can hold it there.

(wRAA + baserunning + positional + replacement) ÷ runs per win

Everything a player contributed, converted into wins. Baserunning is steals only; the positional adjustment is the standard scale; replacement level is set 20.5 runs per 600 plate appearances below average.

LimitThere is no fielding component beyond the positional adjustment. A shortstop who cannot field gets the same credit as one who can.

(13·HR + 3·(BB + HBP) − 2·SO) ÷ IP + constant

The three outcomes a pitcher controls without help: strikeouts, walks and home runs. Put on the ERA scale by a constant solved from this season's league totals, so league FIP equals league ERA exactly.

ERA − FIP

A positive gap means results have run behind the underlying pitching — usually defence, sequencing, or a stretch of bad luck with runners on. It tends to shrink over a season.

(H + BB + HBP − R) ÷ (H + BB + HBP − 1.4·HR)

The share of baserunners a pitcher strands. The league sits near 72 percent; far above it is a run of good sequencing, not a repeatable skill.

(pitches per inning ÷ 16.2) × 100 × workload weight

Pitches per inning measured against the league norm and weighted by innings carried. 100 is typical. Built here because innings pitched alone treats an efficient seven-inning start and a 115-pitch grind as the same night's work.

LimitA workload proxy, not a medical one. It says nothing about mechanics, rest days or velocity decline within a start.

RS^x ÷ (RS^x + RA^x), where x = ((RS + RA) ÷ G)^0.287

The record a club's run scoring and run prevention imply. The exponent moves with the run environment rather than sitting at a fixed 2, which matters in a league that scores as much as the KBO.

reference matrix × (KBO runs per inning ÷ reference runs per inning)

Expected runs from each of the twenty-four base-out states to the end of the inning. The grid's shape comes from a large modern sample; the whole thing is rescaled so its empty-and-nobody-out cell equals the KBO's own runs per inning.

LimitThe KBO does not publish play-by-play, so the shape of the matrix is borrowed rather than derived. Only the scale is Korean.

odds(batter) × odds(pitcher) ÷ odds(league)

How to combine a hitter's rate with the rate a staff allows. A .300 hitter against a staff allowing .240 in a .270 league does not hit .270 — this is the standard way of resolving that.