Fangraphs displays two types of pitcher’s WAR: fWAR (i.e., regular WAR) and RA9-WAR. fWAR is calculated based on FIP—which itself is largely made up of walk rate, strikeout rate, and home run rate, the things pitchers are assumed to have control over—and is meant to be predictive. RA9-WAR adjusts fWAR by layering on BIP and LOB and is meant to be more reflective. We can see all this side by side on a pitcher’s Fangraphs card. Reference’s bWAR is generally closer to RA9-WAR than fWAR, and to me, is not even necessarily needed as long as I can see RA9-WAR, BIP-wins, LOB-wins, and fWAR all side by side.