Popular theory points especially towards the fatal error he made in depending on his predominant situation, where he downplayed Nobunaga in the Battle of Okehazama and took a break to rest at Dengakuhazama where he had no commanding advantage.
特に桶狭間の戦いに関しては、通説では圧倒的に有利な情勢から信長を軽んじ、明らかに地の利が無い田楽狭間で安穏と休憩を取ったことが致命的となったなどが挙げられる。