How different would WWII's outcome have been if...? (See inside)

We were learning more about WWII in my World History class, and are finishing up learning about the Battle of Stalingrad. Now, from what I understand, Hitler had become extremely unhinged as the war went on, and my teacher said Hitler used his trains to deport more Jews to his concentration camps instead of sending more troops into battle.

All this got me to wondering, do you think Hitler could have actually taken the city if he had more troops there? And would WWII have panned out in his favor if he had?