Other directional notches

Open-face directional notch with larger opening angle

Flat and sloping terrain
Directional notch opening more than 70°
The bottom cut is angled downwards from the felling cut
The felling cut in line with or slightly above the level of the directional notch
+ The hinge remains intact until the tree hits the ground 
- Higher stump height

Inverse directional notch, "Humboldt"

Thicker trees on steep slopes
Directional notch opening at least 45°
Horizontal cut has the same angle as the felling cut
The felling cut is slightly above level of the directional notch
+ Good for tree types susceptible to splitting
+ Low stump height