Explain two main reasons for the allies victory over the axis powers in europe

Hitler's blunders contributed to the allied victory; ex, withholding the Panzer reserves away from local control of Rommel prior to the Normandy invasions. His stance of not retreating, led to the debacle of the Falaise pocket which destroyed many of his best divisions in the west, among them the 12th SS, Panzer Lehr, and others. Hope this helps.