If you DOW russia on turn 1 you “inform” the UK player that Selow is not a concrete possibility and so he SCRAMBLE in atlantic fleets attacks; i immagine this is the reason why you loose 4 planes.
Ah. it’s also possible you loose some other planes in France for AA (i immagine you move to the east the 3 southern germany tanks)
Moscow is not reachable. never. if russian player defend correctly: retreating without defend Leningrad or Ukraine on the second turn of attack.
that’s all or you want to calculate odds?
… unless Japan do something but i really don’t know what… maybe a DOW on turn 1? Bombing Moscow with some air base? i don’t know