A coin toss decides who strikes first. From there the two competitors alternate open-handed strikes, one at a time, with sixty seconds between them.
The strike must land below the eye and above the chin, flush across the hand. Leading with the palm heel is a foul. The defender may not flinch, raise a shoulder or tuck the chin — three warnings and a point comes off.
Regular bouts are three rounds, title bouts five, judged on a ten-point must system that weighs the striker’s effectiveness against the receiver’s reaction and recovery. A competitor who cannot answer inside the count loses by knockout.
What the numbers mean
Human force is measured in Fr, the peak load a strike delivers. Peak velocity is hand speed at impact in metres per second. Average neck force in newtons is what the receiving athlete’s neck absorbs — the number that matters most for how a fight ends.