When confronting an incoming attack, the attack is parried or deflected, and a counterattack is delivered simultaneously. This is not as advanced as a stop hit but more effective than blocking and counterattacking in sequence. Practiced in some Chinese martial arts such as Wing Chun, it is also known in Krav Maga as "bursting". Simultaneous parrying and punching utilizes the principle of economy of motion by combining attack and defense into one movement, thus minimizing the "time" element and maximising the "energy" element. Efficiency is gained by utilizing a parry rather than a block. By definition, a "block" stops an attack, whereas a parry merely re-directs it. Redirection has two advantages, it requires less energy to execute and utilizes an opponent's energy against him by creating an imbalance. Efficiency is gained in that an opponent has less time to react to an incoming attack, since he is still withdrawing from his attack.