Introduction to Klalei Hapsak
Rabbi Sruly Bornstein
The Chakira of Reb Elchanan in Kovetz Shiurim as to when Chazal said halacha like "A" over "B", is it because they determined that "A" is good enough to always just follow, or did chazal go through Shas and it turned out that it was always halacha like "A" Sugya: כללי הפסק