Fangraphs is traditionally tougher on the Rockies compared to its counterparts. It often views players through the lens of “what should have happened” instead of “what actually happened” and measures players differently when it comes to defense. There’s also a big difference between how they calculate Pitching WAR compared to Baseball Reference, which we’ll get into.
If you want to read the formula for how Fangraphs calculates WAR, click here. It’s pretty extensive, though, so examine at your own will.
The biggest difference in how it calculates a position player’s WAR is that it uses UZR (Ultimate Zone Rating) to measure a player’s defensive skills compared to DRS (Defensive Runs Saved). You’ll notice this when it comes to players like Nolan Arenado. His career fWAR sits at 31.3 whereas if you look at Baseball Reference he’s currently at 38.7. Fangraphs also uses wRC+ to measure a hitter’s effectiveness (which factors into WAR) but it’s generally pretty close to how Baseball Reference views players too with OPS+.
The biggest difference you’ll notice for pitchers is how Fangraphs uses a stat called FIP (Fielder Independent Pitching) compared to how Baseball Reference focused more simply on Runs Allowed (read their Pitcher’s WAR calculations here). FIP measures how well a pitcher performs based off how well he can control everything that’s within his power (Walks, Strikeouts and Home Runs).
Essentially anything that’s hit to a fielder has an element of luck attached to it, so Fangraphs doesn’t consider that when calculating FIP. This also ignores sequence, so any outcome of a situation with 2 walks, 3 strikeouts and a home run would end up with the same FIP even though the total runs scored could be different (minimum of 1 run, max of 3).
Kyle Freeland is a perfect example of how Fangraphs’ WAR can undervalue pitchers who pitch to contact. In 2018 he finished with an fWAR of 4.1. That put him in a tie for 7th place in the NL with fellow Rockies starter German Marquez even though Freeland was nearly 20 points better in ERA- (Fangraphs’ Park Adjusted ERA). Over at Baseball Reference Freeland ranked 4th in WAR for NL Pitchers with a WAR of 8.4.
Does that mean that Fangraphs’ calculation for Pitching WAR is inaccurate? Not necessarily. Pitching WAR in itself can be a jumbled mess regardless of the site you’re looking at. Fangraphs just values the Three True Outcomes (HRs, Ks, BBs) more than the other sites as balls in play have elements of luck to them.
Fangraphs is still pretty trustworthy, though. It should be viewed as a good starting point for Rockies players and a way to temper your expectations on WAR. If a Rockie is Top 5 in WAR according to Fangraphs then he’s assuredly a Top 5 player in the league. But Fangraphs is generally the low bar for Rockies players.