RV/100
Run value per 100 pitches — runs a pitch saved (or cost) relative to average.
What RV/100 means
Every pitch is scored by how much it moved the run expectancy, then normalized to a 100-pitch workload so a rarely-used offering can be compared to a primary one. Shown from the pitcher's perspective: positive is good for the pitcher.
What counts as a good RV/100
Higher is better — roughly -1 is poor, 0 average, 1 good, and 2 or better elite.
Also written
run_value_per_100 · rv_100 · pitch_run_value
Source
Statcast