What decisions determined the final outcome at Stalingrad?

Russian Side: The Russian General chose to pull back a little once winter came about so he could let the Russian Winter do its damage to the Nazis. Excellent decision on his part. The Nazis started starving and freezing to death. He also managed to get ships and planes sunk so the Nazis could not resupply their men in Stalingrad. He also had some units of his army take out the Nazi force sent to relieve the Nazi forces in Stalingrad. So The Russian General (whose name I cannot spell!) Zhukov I guess it is, did another brilliant move. He surrounded the entire Nazi Force.

German Side: Adolf Hitler of the demise of his force. He ordered them not to retreat or withdraw. Lousy decision considering his forces became surrounded and they did not have winter clothing, food or ammo. He promised to send a relief force who were stalled by Winter mud and snow. So the poor Nazis were stuck, surrounded and dying off by the thousands each day. As they sat around freezing, unable to fight, the Russians would just walk up to their encampment and just toss in grenades. The Russians had a great laugh over that!

When Hitler was told he had to send clothing, ammo, food, medicine or get his people out of there he just yelled at his generals and told them the army had to keep fighting to the death. He simply could not understand or cared that his men would die from exposure to 20 below zero temperatures. The General finally surrendered to the Russians in hopes of getting his men food, clothes and warmth. No such luck. They were made to march to Siberia.