Reco = Reconstruction data with background and fakes subtracted
Fold Unf. = Unfolded data refolded by the response matrix and multiplied by the efficiency and lumi
χ2unf = (Dataunf - Predictiongen) V-1unf (Dataunf - Predictiongen)
χ2rec = (Datareco - Backgroundreco - Predictionreco) V-1reco (Datareco - Backgroundreco - Predictionreco)
V-1unf and V-1reco include only the data statistical uncertatinties of their respective spaces.