wOBA
Weighted on-base avg. Each PA outcome weighted by its run value. League ~.320.
wRC+
Park-adjusted runs created vs league. 100 = avg, 120 = 20% above.
ISO
Isolated power: SLG − AVG. Pure extra-base power.
BABIP
Batting avg on balls in play. ~.300 norm; extremes regress.
BB% / K%
Walks/strikeouts as % of plate appearances.
FIP
Fielding-Independent Pitching. ERA scale, only HR/BB/HBP/K.
xFIP
FIP but normalizes HR to league HR/FB rate — luck-stripped FIP.
LOB%
% of base runners stranded. ~72% league avg; extremes regress.
K-BB%
Pure command/dominance metric: K% minus BB%.
GB/FB
Ground-ball to fly-ball ratio of batted-ball profile.
HR/FB
% of fly balls that became HR. Lucky/unlucky indicator.