The key factors to me are:
1. The possibility of failure in the Ukraine means the possibility of NO IPCs from Ukraine and the survival of the German fighter, and poor positioning for Russia2. Bad dice at Ukraine are far more disastrous for Russia than bad dice at Belorussia.
2. Committing extra forces to a Ukraine victory means the loss of 3 valuable tanks.
3. Germany’s lost fighter would probably have ended up in Africa or Western Europe on G1 anyways, where the UK and US race to build a navy. It’s a problem for the UK/US, but I find that quite acceptable in light of the UK/US production of 65-70 IPC.
4. Losing the Caucasus early is, I still think, not important. If you produce at Caucasus, you must go to West Russia or Ukraine to go to the German front; Ukraine is, I think, overextension, and West Russia is the same distance from Moscow as it is from Caucasus for this game. Besides which if Germany attacked Caucasus on G1, against a defending force of 4 infantry, that means Germany will have used valuable tanks, or risked air against the Caucasus AA gun (and weakened its attacks on valuable targets like the UK navy and Anglo-Egypt and its subsequent position for a UK1 fleet build). Quite acceptable.
If there were a Belorussian infantry or multiple infantry bid, and no bid in the Ukraine, or if the Allies were going KJF, I would probably think of the Ukraine attack as the better choice. But in a game with no bids at either Belorussia or at Ukraine, I still split about 50/50 deciding between which to hit.
“ItÂ´s true that R could counter (Germany often to reattack and hold Ukr ), but in most games they donÂ´t because they would loose the whole Wru stack”
Honestly, I don’t see the point of a heavy Russian counter into Ukraine on Russia2, particularly if Germany is in position to counter the next turn. It is likely that Germany will have attacked Ukraine with only LIGHT forces, in which case Russia can counterattack with infantry and fighters (not committing the West Russia stack), while hitting Belorussia and Karelia with additional West Russia forces. Only if Germany hit Ukraine with EVERYTHING should Russia even consider using the West Russia stack (because then there would be no German infantry reserve to counterattack next turn), but only if Germany didn’t build massed tanks at Berlin, but even then Russia has the option of attacking Karelia and Belorussia instead, moving units up from Moscow, and waiting for the Germans to overextend to Caucasus, or to reconsolidate to Eastern Europe.