The Germans had a family of three main battle tanks. The Mark IV, which received its first real combat test in May 1940, weighed twenty-seven tons, had somewhat less armor than the Sherman, about the same maximum road speed, and a tank gun comparable in weight of projectile and muzzle velocity to the 76-mm. American tank gun but superior to the short-barreled 75-mm. The Panther, Mark V, had proved itself during 1944 but still was subject to mechanical failures which were well recognized but which seemingly could not be corrected in the hasty German production schedules. This tank had a weight of fifty tons, a superiority in base armor of one-half to one inch over the Sherman, good mobility and flotation, greater speed, and a high-velocity gun superior even to the new American 76-mm. tank gun. The Tiger, Mark VI, had been developed as an answer to the heavy Russian tank but had encountered numerous production difficulties (it had over 26,000 parts) and never reached the field in the numbers Hitler desired. The original model weighed fifty-four tons, had thicker armor than the Panther, including heavy top armor as protection against air attack, was capable of a speed comparable to the Sherman, and mounted a high-velocity 88-mm. cannon. A still heavier Mark VI, the King Tiger, had an added two to four inches of armor plate. Few of this model ever reached the Ardennes, although it was commonly reported by American troops. Exact figures on German tank strength are not available, but it would appear that of the estimated 1,800 panzers in the Ardennes battle some 250 were Tigers and the balance was divided equally between the Mark IV and the Panther. Battle experience in France, which was confirmed in the Ardennes, gave the Sherman the edge over the Mark IV in frontal, flank, and rear attack. The Panther often had been beaten by the Sherman during the campaign in France, and would be defeated on the Ardennes battleground, but in nearly all cases of a forthright tank engagement the Panther lost only when American numerical superiority permitted an M4 to get a shot at flank or tail. Insofar as the Tiger was concerned, the Sherman had to get off a lucky round or the result would be strictly no contest.