Max effort low box squat (like normal high bar back squat, but to the box)
5-4-3-2-1-1-1-1
2min recovery
Proceed by following steps:
5r @ 40%, 4r @ 50%, 3 @ 65%, 2r @ 75%, 1r @ 85%
At this point extend your rest to 2min between sets.
1st. 1r @ 95%
2nd 1r @ 100%
3rd 1r @ +100% (new pr attempt)
Do not overestimate the weights on last set.
Be smart! For real!