Female power punch

This machine measures speed, not necessarily strength. So, stronger punch would lose to a faster one. UPD: let me clear the confusion. The machine measures kinetic energy you can transfer to the bag. Mass of the bag is constant, so the only variable that can be measured is speed of the bag. The speed of the bag depends on two things: the amount of energy you have and the time you have to transfer this energy. And you can't substitute one thing for another: neither bullet with high speed, but low energy, nor heavy paver moving at walking speed would get you 999. If the bag is relatively light then the speed of your punch matters more then your overall energy - it doesn't matter how much energy you have left after your fist stopped touching the bag. It's because energy transfer stops when speed of your fist is equal to the speed of the bag. With better speed you can transfer energy for longer, and thus transfer more energy. And that's why a punch that can make a hole in the wall could lose to a faster one with less kinetic energy behind it.