player size:
height 72
width 32

minimal space needed for a player to fit through:
width 31
crouching 49
walking 70

maximal height for a ledge to ledge-climb with a single jump:
114

falling damage:
201+

maximum height for 3x walljumps is also around: (without having to pull yourself up)
200/201

aha and what the matter is the reason for this??

Rofl, there's some post in teh mapping that isn't by Steve......