FG just made a post about how they have improved their defensive metric, UZR. Long story short, they now base hit designations on hang time rather than someone deciding to call it a LD, FB, or GB.
https://www.fangraphs.com/blogs/inst...nd-uzr-update/
They then retroactively applied the results all the way back to 2012. This obviously changed some players' defensive ratings...sometimes by a lot. How much? Here's a sample of some of the largest changes from recent seasons:
2016 Cespedes from -12.1 to -4.0, a 8.2 change for the better.
2016 Pillar from 21.5 to 12.3, a 9.2 change for the worse.
2015 Uribe from -1.3 to 6.7, a 8.0 change for the better.
2015 Kiermaier from 23.2 to 11.8, an 11.4 change for the worse.
We see a lot of the extreme defensive values brought closer to the middle. Inciarte from 11.8 in 2014 to 4.1. Simmons from 22.8 in 2013 to 11.7. Search for Kemp..many of those terrible seasons weren't so terrible after all.
My biggest issue with UZR was always the crazy outlier seasons it spit out for excellent and terrible players. It looks like now they have finally figured out how to reign in those seasons in question.