I read stories all the time of how lucky German soldiers were not to be captured by the Russians, but at the same time I'm unable to find why they were so "lucky." Why did Germans fear being captured by the soviets?
Over 3 million Red Army soldiers died in Germany captivity. This didn't exactly discourage Soviet mistreatment of German POWs.
The official Soviet tally is 381,067 German POWs dying in Soviet captivity.
The chances of German POWs dying in Allied captivity and vise versa were much lower.
"Soviet Casualties and Combat Losses in the Twentieth Century", Greenhill Books, London, 1997, G. F. Krivosheev
G. I. Krivosheev. Soviet Casualties and Combat Losses. Greenhill 1997 ISBN 1-85367-280-7 Pages 276-278.
There was no instituted mistreatment of german POWs. War Propaganda and German Crimes made them very hateable for every Soviet. So mistreatment happened, a lot, but it was never an instituted policy to murder POWs.
Thing is, the Soviet Union could barely feed themselves, so there wasn't much to go around. Officials could rarely justify to feed the attacking soldiers when their own population was starving.
German fear of reprisal was very big. Operation Barbarossa is one big robbing and murder spree. Many Germans were afraid that they get treated the same way. This fear was also fed by Social Darwinist state policy that it is a race war for survival. Gladly for Germans, the Soviet Union didn't act out severe revenge.