What gives Ender the confidence that he can survive Battle School?

Ender Wiggin's confidence in surviving Battle School stems from his exceptional intelligence, strategic thinking, and natural leadership abilities. Early on, he demonstrates a talent for understanding complex situations and adapting quickly, which sets him apart from his peers. Additionally, Ender's previous experiences, including his success in simulations and games, bolster his self-assurance and belief in his capability to thrive in the competitive environment of Battle School.