There are a great number of martial arts that teach practitioners to focus on striking an opponent to defeat them in a self-defense altercation. Strikes can be effective in self-defense. If the person defending themselves from a street attack can strike first and can hit harder than the assailant, these strategies can work. Martial arts like traditional karate, tae kwon do, kung fu, or sports like boxing are common examples of striking focused fighting styles.
Let's consider circumstances when striking based strategies are less likely to be a good solution in a self-defense confrontation.
The attacker is stronger/ more athletic than the assault victim
Optics and Video evidence
The attacker has more experience in fist fights
Close quarters do not allow enough space to use kicks or powerful blows
Drugs/ alcohol or rage have reduced the attacker's sensitivity to pain
The victim injures their hand by throwing strikes
Striking always compromises base
Let's look at each consideration one at a time, although more than one could apply in any assault scenario :
BIGGER, STRONGER, MORE ATHLETIC ATTACKER
This consideration likely applies to most self-defense scenarios. A predator is not likely to choose a victim who is clearly a superior physical specimen to them. One reason a victim is chosen is that an assault appears to the would-be perpetrator to be a successful endeavor to achieve whatever their goal is. Presuming this means the attacker will typically be more physically gifted that the victim, the conclusion should be that blow for blow, the more athletic attacker will have an advantage.
OPTICS AND VIDEO
In those unlikely cases where we are bigger, stronger, or more athletic than the attacker, strikes may seem more realistic to end the fight. This may be true. If we defend ourselves from a smaller person by beating them down with caveman blows, we create a risk that we may appear to be the assailant to anyone who did not see how the confrontation began. All of us are subject to an amygdala highjack in the heat of a violent confrontation. If our trained plan A to deal with aggression is by striking, it is MUCH easier for our overly aroused brain to go overboard with vicious strikes and set us into caveman mode. If our training leading up to the confrontation is based on more intelligent strategies, we will be more likely to be able to resist our caveman instincts and control the situation without appearing to be the violent aggressor.
FIST FIGHT EXPERIENCE
If a person is walking down the street and is confronted by an unarmed attacker, a safe bet could be made that the attacker has been in fights before and is not scared of a fist fight. Experience fighting is a huge factor in limiting how much paralyzing anxiety a person will feel while involved in a physical altercation. Most of us who study martial arts of any kind probably do not find ourselves getting into street fist fights on the regular. In this regard, an attacker on the street will usually have the advantage of experience in a contest of strictly blows.
NO SPACE TO FIGHT
Practice sessions in striking-based arts typically occur on the training mat. Other students move off of the mat to give plenty of space to move around and to execute large movements to set up spinning kicks, etc. There are no people, chairs, tables, cars or other real-world obstacles on the mat. Street self-defense locations are not likely to share these controlled variables. Therefore, if a martial artist has spent years perfecting a jump spinning tae kwon do kick to win in tournaments, the environment of the bar or alley where an attack occurs will not likely accommodate big spinning movements that may be needed to generate effective kicks.
NOTHING SEEMS TO HURT THIS GUY!
Some people are not terribly bothered by being punched. It is very possible, if not likely, that an attacker on the street has been using alcohol or other drugs. A person under the influence of enough drugs or the right kind of drugs will not react to being punched or kicked the way a sober person would be expected to. Their physical pain tolerance can be extremely enhanced, or their brain could be impaired to the degree that they just aren't concerned about the pain they do feel. Unless a blow is precisely placed and powerful enough to knock a person unconscious, a strike may be at a minimum useless, and at worse, provoke an even more angry, violent response from the assailant.
YOUR LIMBS ARE FRAGILE
It is common for someone who strikes another wit their fists to walk away with broken bones in their hand. Even if a strike with a fist to an assailant's face knocks them out and ends the fight, having to go get x rays and see a doctor about a broken hand is not a win. Remember Anderson Silva vs Chris Weidman when throwing kicks. If your leg hits a shin bone or a chair or table that is next to you, you can end up with a broken leg or ankle. Striking in general involves hurling your arms or legs at high velocity in a fight. Contact with anything hard or immovable will result in injury to your limbs.
GOOD BASE OR STRIKE- PICK ONE
Any point in a fight at which time the assailant and victim are in contact with each other, the person defending themself must have control of their balance/ base. Most striking attacks require a person to sacrifice their base in order to generate the acceleration required to generate a powerful strike or kick. For example, if an attacker has grabbed a female by the wrist and is trying to drag her over to a near-by van with no windows, the victim can best prevent being walked to the van by taking a wide base stance and lowering her center of gravity away from the pull. If the victim were to pick up a leg to try to deliver a kick, or wind up to throw a strike, she will have no base and will stumble in the direction she is being pulled.
SO WHEN CAN STRIKING BE USEFUL?!
Strikes are a viable tool in jiu jitsu. In spite of the above outlined concerns, strikes can be important in implementing jiu jitsu principles.
A jiu jitsu practitioner may use a strike to create a useful reaction by the assailant. For example, a jab toward the face will likely cause an attacker to retract their hands upward to protect their eyes, jaw, or nose. Although a jab will not typically end a fight, the reflexive movement of the hands upward, and the mental distraction of having the defend their own face, can make quickly lowering and shooting for a double leg takedown more successful.
Another example where jiu jitsu uses strikes to create a reaction is from the mount. Once a jiu jitsuka mounts an assailant, a flurry of moderate strikes (even open hand slaps) can be thrown toward the face of the attacker. This will almost certainly cause an untrained opponent to try to cover their face and instinctively turn to their stomach. The attacker is then set up for a vascular restraint hold and the attack is over.
Another purpose to applying a strike or a kick to an opponent is to off-balance them. This is most commonly seen in Japanese jūjitsu or judo self-defense techniques. A strike to the face or an open-hand blow to the ear may be used to cause the opponent to reel back or to rock back onto their heels just for an instant. During that instant, a takedown or a throw may be applied to capitalize on that weakness in the opponent's base.