Don't think this happens in Bitter End. I think I need to add an instant ending once one side is wiped out.
Well, for me it's not really that "the other side is wiped out". Yet. But at 2M- SU troops vs 4,5M just Germans, all I face is logistical issues. How fast and how smart I can move those FBDs. All SU units I encountered during the last 10-12 turns have an attack value of 1, and we are in the summer. Even the Corps don't have more than 3-4k men in them (although an occasional Tank Corps can have 200 AFVs in it, and loose them all as it shatters - no experience etc.) The Soviets still produce quite a lot, and, certainly, get a lot of Land Lease, so they are not "wiped out". I don't think they can do anything to surprise me, though... as long as I can be on the bounce protecting those rail tracks against the Partizans. After clearing the Caucassus (3-5 more turns, so by later August 42), my game will change into a push towards the NE corner, shortening the front considerably (and freeing all of them Rumanians and Italians for RR protection duty). As it is now, it will be just a sensless infantry grind through the heavy woods that may extend well into the 1943. Bitter End indeed.