K-BB%
Strikeout rate minus walk rate — single best summary of pure stuff + command.
What K-BB% means
Subtracts walks from strikeouts on a rate basis. League average ~14%; > 20% is elite, < 10% is concerning.
What counts as a good K-BB%
Higher is better — roughly .100 is poor, .140 average, .180 good, and .220 or better elite.
Also written
k_minus_bb_pct · K−BB% · kbb_pct