Complex sentence: Regarding horsemanship skills, which Kassai places equal emphasis on, the aspiring horseback archer must practice first without a saddle-to promote good balance-and once past a certain level the archer may graduate to use a specially modified Eastern Saddle.
Split into simpler sentences: Regarding horsemanship skills, upon which Kassai places equal emphasis, the aspiring horseback archer must practice first'bare-back' (without any saddle) to promote good balance. Once past a certain level the archer may graduate to use a specially modified Eastern Saddle.