WARP - Pitcher WARP computed using DRA, roughly IP/9 * ([Replacement RA]-DRA) / [Runs Per Win].
WARP SD - Standard Deviation of WARP
DRA - 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 SD - Standard Deviation of DRA
DRA-Minus (DRA-) - Much like ERA-minus and FIP-minus, DRA-minus is a scaled version of DRA, centered at 100, intended to compare pitchers across seasons by the way they compare to their peers. The formula for DRA-Minus is DRA / DRA_mean * 100.
NIP Runs - "Not-In-Play" Runs. Runs saved or given up over average in walks (both intentional and unintentional), hit-batsmen, and strikeouts. The pitcher's contribution to each of these metrics is fit by a mixed model, and the resulting likelihoods are multiplied by the linear weight of each event type.
Hit Runs - Runs saved or given up over average in terms of hits yielded. Put another way, when the pitcher gives up hits, how hard does he get it? We model home runs, triples, doubles, infield singles, and outfield singles separately. The pitcher's contribution to each of these metrics is fit by a mixed model, and the resulting likelihoods are multiplied by the linear weight of each event type.
Out Runs - Runs saved or given up over average in terms of outs generated on balls in play. We model single-out putouts at each fielding position separately, and also do so for multi-out plays beginning at each infield position. The pitcher's contribution to each of these metrics is fit by a mixed model, and the resulting likelihoods are multiplied by the linear weights of single and multi-out plays as appropriate.
Framing - Runs saved or given up over average in terms of Framing (CSAA) for this pitcher.
