Tinsley-Wallerstein diagrams for the stars in our sample alongside with the rest of the APOKASC catalogue version 1 (top panel) or version 3 (middle and bottom panels). The blue lines indicate different thresholds between α-rich (“AR”) and α-poor (“AP”) stars: Eq. (1) for the middle panel and Eq. (2) for the bottom panel, see Sect. 2. Filled symbols represent stars whose mass is above 1.3 M_⊙ and open symbols represent stars with masses below that limit. The mass is taken from APOKASC-1 (top panel) or APOKASC-3 (middle and bottom panels). The bottom panel indicates our final classification as YAR, α-rich (AR) or α-poor (AP; see text).