CORSE 4x4 - driving technique. Same vehicle, different vehicle, different drivers
CORSE 4x4 - 2 different vehicles, 3 different drivers, 3 different lines. Trials comp 101 - Doesn't matter on the vehicle (to a certain extent) it's all about the line you pick.
Driver on far left of screen - one shot completes it
Driver in the middle, 1 attempt, that was enough
Driver on far right, same vehicle as the left but different line. It was just enough to unsettle the vehicle, the traction, the momentum to not make the climb.
Trials is all about keeping attempted forward motion. That means in simply terms you don't intentionally roll / move backwards. The vehicle can hit a rut, a root, an edge or lip, the vehicle bounces but the wheels are still turning forward.