Everyone is unique. No two people are the same. But people often share common attributes that can be used to construct a strategy for defeating or dominating someone who wishes to be belligerent. What we will talk about are generalizations. You cannot be certain that any one strategy will work against any particular person, even if they do fit a general body type or description. Any individual may behave completely contrary to the descriptions provided below.
A person who is quite tall will generally try to use distance to their advantage. They will use their relatively longer limbs to keep you away from them. They will consistently attempt to strike from a distance, usually from a distance that is just outside your normal reach. These individuals are often willing to move around quite a bit in order to keep themselves at an advantageous distance from you. They are more likely to strike to your upper body than to your lower body when using their hands simply because they will generally be striking downward due to the relative height differences. Due to the angle of their strikes your upper body is a more convenient target than your lower body (though a trained person will kick to your lower body without hesitation).
Individuals who are relatively stout are more likely to wade directly forward in order to get inside of your reach. This allows them to take advantage of shorter range strikes and their relative strength. They will seek to minimize movement as that is both tiring and risks them being forced to the outside again.
When someone is quite heavy or obese they seek to use their greater overall body mass and strength to their advantage. They will work to move inside your reach and then push, grab, slam, or strike you so they can use their greater mass against you. Grabbing is particularly common as it keeps you from escaping and allows them to continue to punish you while minimizing their need to move around, which is quite tiring to a larger individual. Large people generally do not have well defined musculature, but they are nonetheless extremely strong. Do not make the mistake of assuming that a large individual is also slow. Even quite obese people can often move very quickly.
Obese individuals often have weak lower backs. In the heat of an engagement when adrenaline is plentiful, they may not exhibit any weakness in this area of their anatomy, but it is an area that is susceptible to direct or indirect attack in some instances.
If a person is quite thin then they are quite often very agile. They can bend and contort their bodies in ways you may not expect, allowing them to readily escape or to quickly attack you. These individuals are more likely to jump as a method of attack or escape than people who are of a stockier build. They are also more likely to employ darting behaviors where they attempt to enter, strike, and then quickly exit again. They are seldom interested in staying inside where they will have a relative weight and strength disadvantage against a larger opponent.
A shorter person will deliver a higher percentage of their strikes to your lower anatomy than will a taller person. They will again seek to get inside of your reach to minimize your opportunities to strike them while maximizing their opportunities to inflict harm. They may seek to attack your legs in an attempt at Nage or to inflict pain or damage to these extremities. They will also seek to use their relatively lower center of gravity to their advantage, often trying to induce or force you to bend forward or backward so that your center of gravity is no longer over your legs.
Muscular people are obviously often quite strong. But this does not mean their strength is evenly distributed. Someone who is clearly a body builder will commonly have strong legs as well as a strong upper body. But someone who only works on their upper body for aesthetic purposes may have relatively weak legs. The extra muscle mass carried by these individuals does not mean they are slow or have slow muscle reflexes.
Bodybuilders are often well aware of how to develop fast twitch muscle fibers. These individuals will commonly have good short term endurance, excellent speed, and obvious strength. They will often try to use strength instead of skill to dominate an opponent. This will not be the case if the person is a MMA fighter or Jujitsu practitioner. As a generalization, these individuals will seek to get in close so they can directly apply their strength advantage against you.
It will benefit you to study people and various body types in general. Look for characteristic patterns of movement for various common body types. Evaluate the likely strengths and weaknesses of each body type. Consider how these individuals might behave in a conflict, then think about how you would counter their natural fighting tendencies. When working with training partners of various body builds, test your theories for validity. Evaluate which counter measures work well against an individual of a specific build, and those that have little chance of success.
When you first encounter a hostile individual you will want to immediately assess their state of mind, potential weaponry, and their body type. These can help you try to diffuse the situation and react appropriately in the event of an attack.
You will also want to notice other potential advantages and disadvantages the person may possess. Do they have long hair? Do they have a beard or mustache? Do they have piercings? Are they wearing thick or baggy clothing? Are they wearing heavy boots? Do they have any physical disabilities? Are they inebriated in any way? Do they appear to be rational? Are they wearing glasses of some type? Do they have friends?
These things can suggest tools you can use to your advantage. Grabbing long hair or a beard can provide an effective point of leverage. Baggy clothing can provide another leverage hold. Glasses and piercings may afford you with a mechanism to inflict pain or initiate pain compliance. Obvious physical limitations can provide you with a strategic advantage.
But something like heavy boots, a thick leather jacket, a motorcycle helmet, winter gloves, snow goggles, or similar apparel may suggest things that limit your opportunities. Clearly you will not want to punch to the side of a helmet or allow someone to strike at you with gloved hands.
It will also be advantageous to notice how the person is standing. Is one leg back? Are the feet together? Does the person slightly lean to one side or the other? Is the person’s head tilted to one side or the other? Does the person seem to hold his or her shoulders back? Is the body twisted so the person’s center is oriented to your left or right?
All of these things may indicate a possible plan of attack. If the shoulders are back you might anticipate a potential kick. If one leg is back the person may plan to strike you with that side of their anatomy. A slight lean may suggest the person plans to move in that general direction as the initial part of an attack strategy. There are no guarantees that any of this will occur, but it offers you some potential clues into the person’s state of mind.
You may only have a split second to take in as much of this information as possible. Consciously and unconsciously noticing as much information as possible will allow you to better deal with an individual in the event they attack you. Training with a large variety of people of varying physical characteristics will afford you with an unconscious sense for how to effectively deal with people of nearly any body type.