You'd have to dig through the BPro site for the math, but their WAR is based of their DRA calculation, which is generally defined thusly: Deserved Run Average (DRA) uses a collection of mixed models to tease out the most likely contributions of pitchers to the run-scoring that occurs around them. Unlike other component metrics, DRA considers (and adjusts) home runs and balls in play, and achieves significant improved reliability over the raw versions of those and other statistics. DRA has equal descriptive power to Fielding Independent Pitching (FIP), and offers much improved reliability and run prediction. DRA is park, platoon, framing, and opponent-adjusted, and is scaled to follow the distribution of RA9. From 2008-onward, it includes specific characteristics of the subject pitch, as tracked by PitchInfo. It also includes the pitcher's command runs (from CSAA), basestealing runs (SRAA and TRAA), and errant runs (EPAA).