ORIGINAL: Flaviusx
Most of the lower Volga is swamp behind major river. This is pretty easy to defend. Not quite impassable, but damn near. A single rifle division should stop the panzers here, and the German is going to have a difficult time mustering enough infantry to force a crossing.
Yes, you're right - I should have covered that spot. I just assumed the river not to be fordable.
ORIGINAL: Flaviusx
There is a weak spot just south of Stalingrad that should be heavily defended.
Parenthetically, I notice you are not using rifle corps. My own view is the Soviet should try to build one a turn in this scenario, although APs are tight. These make a big difference defending major objectives. Indeed, the rifle corps is arguably the single biggest upgrade available for the Soviet Union taking the long view and I try to stock up on APs going into June of 42 to begin aggressively converting.
Once you get a few such corps into and around Stalingrad, the German is going to have a hell of a time taking the place. They also dig very well and have strong construction values.
I've noticed some other Soviet players ignoring cavalry corps going into the first blizzard. Build these as well.
So far as this particular scenario goes, avoid building tank corps. Not cost effective. You get plenty of these for free as it is, and they are stuck with the understrength 42 TOE. You can get 2 rifle corps for the same price and get much more out of that immediately as their TOEs directly translate unlike tank brigades going into corps.
Thank you for the advice about Tank and Rifle Corps, they're very sturdy formations, which pack quite a punch (for 1942 Soviet infantry). I considered that but I consciously chose not to do it. Let me share with you my view (and assessment) of the situation (perhaps you'll find some flaw here as well).
When I opened the first turn, I found that
all the armies west of the Voronezh-Voroshilovgrad-Rostov line were encircled, and very few troops were in a Ready status, which doomed my break-out attempts due to lack of "ooomph". Only one Tank Corps was able to retreat to the east (being encircled and destroyed three weeks later around Boguchar).
On Turn 2, my opponent brushed aside the few troops I had been able to muster to cover the Don section between Voronezh and Boguchar, encircling Voronezh (including the frozen army that starts just north of the city as well as two Guards Rifle divisions), as well as getting another big encirclement around Voroshilovgrad.
This had the side effect - due to a bug on reinforcements entry hexes being occupied by the enemy - of putting out of action the entire 5 Tanks Army (minus the HQ).
By turn 3 I had just one battered and demoralized tank corps and a severe lack of infantry (we've been on infantry parity since then).
So forming Rifle Corps didn't look to me very sensible at all: I had to maximize frontage to avoid further encirclements, I didn't want to risk having one of those expensive Rifle Corps to get pocketed and destroyed.
I tried to keep an active defense, which has successfully prevented my opponent to reach Stalingrad till this turn. Rostov fell this turn as well (no rifle corps there either, kept the guys there supplied by air during two turns).
Besides the lack of infantry, another reason for not building those corps was that I preferred to reorganize my chain of command, which has been thrown into severe disarray several times already.
I have just built one tank corps: I tend to see Soviet corps formations as making sense in the offense, in the defence, I see their use, but I wouldn't say they're a recipe guaranteeing success
Sorry for the long post, but I think the situation deserved an explanation.