"The best measure of the Allied advantage was in terms of military hardware, however, since it was with capital rather than labour - with machinery rather than manpower - that the Germans and the Japanese were ultimately to be defeated. In every major category of weapon, the Axis powers fell steadily further behind with each passing month. Between 1942 and 1944, the Allies out-produced the Axis in terms of machine pistols by a factor of 16 to 1, in naval vessels, tanks and mortars by roughly 5 to 1, and in rifles, machine-guns, artillery and combat aircraft by roughly 3 to 1. Blitzkrieg had been possible when the odds were just the other way round. Once both sides were motorized - one of the defining characteristics of total war - the key to victory became logistics, not heroics. The fourfold numerical superiority of British armour was one of the deciding factors at El Alamein. The average ratio of Soviet to German armour at the beginning of the offensives of 1944 and 1945 was just under eight. The ratio in terms of combat aircraft on the Eastern Front rose from three in July 1943 to ten by January 1945. Likewise, Allied dominance of the skies ensured the success of D-Day and guaranteed the ultimate defeat of the Germans in Western Europe."