The 1917 mass advance only worked because the Soviets put up ZERO resistance
Perhaps you can also explain why these mass advances worked, all of which were opposed by serious resistance.
1. August 1914 attack across Belgium and into Northern France.
2. May to September 1915 advance to Brest-Litovsk
3. Fall 1915 destruction of Serbia.
4. 1916 destruction of Romania.
5. Fall 1917 destruction of the Italian army, which was only stopped by the movement of an entire Anglo-French field army to the Piave.
6. Spring 1918 destruction of 2 British field armies.

Could it be possible that the German army knows what they are doing and have enough firepower to gain the advantage when they chose to do so?