sentences:  Today he continues to serve as the senior Mashpia in the central Lubavitcher yeshiva at 770 Eastern Parkway.His position as leading Choizer and Meiniach makes him the default authority on the Rebbe's teachings specifically, and he is universally recognized as the greatest scholar of general Chabad Chassidic doctrine and thought.He is referred to familiarly amongst Chabad Chasidim as Reb Yoel.