General Winter: The Greatest Soviet "General"
The basis of Hitler's plan to invade the USSR was time. The campaign's success rode primarily on avoiding the brutal winter and not repeat the same mistakes as the great Napoleon. Obviously Hitler failed to do so. The Germans were ill-prepared for the severity of the Russian Winter. The Red Army knew exactly what to expect and had generations of surviving and fighting in the extreme cold, but the Germans did not. (Fun fact: Soviet soldiers would sleep with their guns next to their bodies to prevent them from freezing.) The Russians were equipped with heavy boots, coats, and gloves, while the Germans had standard-issue winter uniforms which was hopelessly inadequate against General Winter. In addition, German tanks were more advanced than Russian tanks; however, they broke down frequently and were much more complicated to repair, making them more of a liability than an advantage. This simplicity also allowed Russians to mass-produced their tanks at a higher rate than they were destroyed.