Five Ways of Attack

The Simple Angle Attack (SAA) or simple attack (SA) - This is, simply, hitting or kicking the opponent at the precise moment of an opening. It is a difficult aspect to master as it requires mastery of timing, range and speed. The majority of attacks used in boxing are simple attacks.

Attack by Combination (ABC)- this is using two or more percussive attacks in combination to elicit a specific response from the opponent, creating an opening so the final blow or blows land unobstructed. Also seen in boxing, the classic example is the one-two, which is a jab to the chin and then a cross to the jaw. The jab raises the chin to expose the jaw, which causes a knockout if hit right.

Hand Immobilization Attack (HIA) Bruce named it HIA but it can stand for Head or Hair as well. This describes the trapping and grappling ranges of fighting, Where the fighters are attached to each other either by the work or one or both fighters. In Boxing, this is known as the clinch, where you close distance with the opponent and work to 'hug' him so he can't punch you. In streetfighting, as Bruce points out, you can do things like headlocks and hair pulls as well. So it's important to remember that they are a part of HIA. HIA can also include the feet or legs, so maybe just call it Immobilization attack or IA. Generally HIA is more used to control the opponent and to segue to other attacks.

Attack By Draw (ABD) This is when you let your guard down on purpose to get the opponent to attack you in a way you'll be ready for with a counterattack. If you are familiar with Aikido, this is pretty much the only strategy aikido uses, relying almost entirely on passive deflections.

Progressive Indirect Attack (PIA) This is to move in to attack, faking your angle of attack on the approach to elicit a defensive response from the opponent, then changing the angle to the real angle of attack thus scoring a hit. In a nutshell, fake low, hit high. This idea comes from Western fencing.