Hey guys. I'm playing every zombie map on solo and I want to do it in order of which they were released. So NDU, Verruckt, SNN, etc.  
 
Nacht der Untoten is giving me so much trouble and I think it is because of the very limited space in the map. (No perks doesn't help either lol) 
 
But basically, I would consider myself an above-average zombie player, especially in solo. But I cannot figure out this map. Does anyone have any sort of tips/strategies to get to a high round for this map? I've seen a few strategies and I've tried those but I can't figure it out. 
 
Any help would be appreciated. Thank you!  :D