In my current game against Isokron, I have had the misfortune of being on the receiving end of a highly effective strategy; the successive bombing by the Wehrmarcht of the 4 bridges located at Nowocherask (close to Rostov - the Rostov bridge also works), the bridge at bystralia (between Kamensk and Morowsky), the bridge at bobroff, and the bridge righ behind voronezh.
Blowing up these 4 bridges will completely deny the soviets ANY rail movement west of them. Now, I don't blame Isokron for using this strategy - it works, and it is fair game. But I hope we can agree that it doesnt make ANY sense whatsoever. I had (naively) assumed that, as long as a railway can reach a map edge - any edge - trains could travel along it (the assumption of off-map movement, and all that). Not so it turns out. Despite having several railways reaching the northern map edge at several points which were, historically soviet territory (and stayed so through the entirety of the campaign), no trains can come at all.
Moreover, the area cut off from rail transport is 150 km wide, reaching all the way from Voronezh down to the Black Sea. Are you really trying to tell me that blowing up 4 bridges means that there is not a single train left to ferry troops around within this massive area?
This is the first rule I have seen in this game that I am really angry with - it makes no sense at all, and really needs to be addressed.
PS: Isokron, I haven't given up on our game yet (though you are kicking my butt now) I am simply away for a few days for the new year!
"Hard pressed on my right; my left is in retreat. My center is yielding. Impossible to maneuver. Situation excellent. I am attacking."
-Gen. Joffre, before the battle of the Marne