Complex sentence: Bitzer, regarded as the Father of PLATO, succeeded because of his rejection of modern educational thinking, and returning to a basic drill-based educational system; his team improved existing systems by allowing students to bypass lessons already learned.
Split into simpler sentences: Bitzer, regarded as the Father of PLATO, rejected modern educational thinking, and returned to a basic drill-based educational system. His team improved existing systems by allowing students to bypass lessons already learned.