There are only a few effective blocks that can be performed with the weapon. The weapon is normally considered to be an offensive, not defensive weapon. Nonetheless, there are some blocks with which you will want to become familiar.
Perhaps the most obvious block is to hold one stick in each hand using a standard grip and pull the chain or cord taught to present the entire weapon as a blocking surface. This type of block can be applied in nearly any orientation that can be established by your hands. The block also has the advantage that you may be able to wrap the cord around the incoming arm or weapon and then perform some form of subsequent controlling action.
The disadvantage of this block is that a powerful strike into the cord or chain could cause the weapon to fold inward. If your block was not placed at a sufficient distance from your body then you might still be impacted by the incoming strike. If you are using a corded weapon and the incoming strike is from a bladed weapon then the cord may provide little defense against the strike. As with all blocks, you will want to be selective about how, when, and where you apply this type of block.
If you grasp one or both sticks by holding the corded or chain end in the palm of your hand then the stick(s) become a hard surface that can protect your forearm. This makes a good blocking surface (and striking surface, as discussed later).
Some people refer to various spin actions as blocks. The view is that the spinning weapon placed between yourself and an opponent will block or deter any likely incoming strike or approach. It is fine to think of this as a block, but also consider that while you are performing this block your opponent is computing how they will overcome your dynamic yet also somewhat static block. Maintaining such a blocking action for a prolonged period will provide your opponent with enough insight to consider a possible way around your attempt to keep him or her at bay.
I do not mentally think of a spinning action as a block, but if it makes sense to you then by all means use it as a mental model. I prefer to think of these types of movements as a stalling technique rather than as a block. My intent is to momentarily stall or disrupt an opponent’s attempt to move closer. I never stall for more than a few seconds. Then it’s time to do something more purposeful – before my opponent has figured out how to handle my stalling attempt. I mention all of this because you will see videos and other descriptions of the Nunchaku that refer to spinning motions as blocks. These people are not wrong. They are only using a different mental model.
There are numerous different strikes that can be delivered using the weapon. The most obvious are those involving some form of swinging action. But you will want to consider, practice, and utilize the many other strikes available when utilizing this flexible and powerful weapon.
The most common striking method for the Nunchaku is to hold a control stick in one hand and cause the free stick to fly through the air in a circular path toward some target. The angular velocities involved can be quite tremendous resulting in a high energy impact upon any surface that is contacted with the full force of such a swing. These strikes can be delivered in a horizontal, vertical, rising, falling, left, right or anywhere in between motion. It is common to deliver a flail strike, wrap the end of the strike around some body part, and then accelerate the weapon in the opposite direction with another flail strike. With practice you will be able to move in a continuous manner from one strike to another without stopping or hesitating. It is the primary reason why this weapon is so effective.
Flailing strikes can be accomplished by holding the weapon with a standard grip and then swinging the arm in a forward or reverse swinging action. With either swing some last minute wrist motion can also be used to suddenly increase the kinetic energy of the weapon just prior to impact.
Holding a stick with a reverse grip may also allow the weapon to be used as a flail. Because of the hand position this often has less reach than a flail with the stick held in a standard grip. This is usually not an appreciable problem but it is something you should consider when using a reverse grip.
Another potential flail strike is to hold the weapon by the cord or chain and swing the weapon such that the opposite end of both sticks strike a target. There is a serious potential for unintended recoil from such a strike, but with enough attention to this potential problem you can make this an effective strike should you be holding the weapon in this manner.
A common flail strike is to catch the free stick under your arm on the same side as the control stick. You then raise your elbow to release the free stick and strike directly toward angle one with a downward motion of the control stick. As the free stick completes its circular movement it will again move up and under the arm whereupon the elbow pulls in toward the chest wall, trapping the free stick between the arm and the chest. This rapid strike can be repeated as often as necessary. Some practitioners refer to this as “popping the clutch.” With the advent of automatic transmissions and self-driving cars this terminology may be losing its relevance. Perhaps we should use something like “whiplash”, “denting the dragon’s forehead” or “mantis strike” to describe the motion. Whatever it’s called, it’s pretty fast and effective.
This is a rather ineffectual striking sequence but you will see it demonstrated often in videos and presentations. The two sticks are held with a standard grip in one hand, but the sticks are staggered so that the chain or cord is stretched tightly between the two ends. The stick on top is slid forward in order to stretch the cord/chain taught.
Now the weapon is rapidly accelerated toward angle one. Midway through this swing the grip on the top weapon is released, causing the non-corded end of the weapon to shoot forward much like a harpoon. The goal is typically to strike an opponent in the face or eye with the blunt end of this stick. This is much like the motion or movement that one might use with an Atlatl.
While it is possible for this strike to work, it normally requires that two hands be used to properly position the two sticks in the one hand. While this can be done with one hand, it requires a specific planned sequence. There may be better things you could be doing in the same time frame.
This strike is almost always shown and demonstrated using an overhand delivery. There is no reason the strike can’t be delivered from either side or from any other angle for that matter. Experiment with different angles of delivery to see how these might be utilized.
Thrusting strikes can be accomplished by using either end of one or both sticks. If both sticks are held in one hand then either the corded/chain or non-corded end of the sticks can be used in a thrusting action. If only a single stick is being used then either end of that stick might be employed in a thrusting manner.
In practice Tsuki strikes can become somewhat awkward or tenuous. The length of the cord might cause a thrusting strike to fall short of its potential when the opposite hand causes the cord to stretch to its maximum length. Holding two sticks in one hand can cause the sticks to become jostled and dislodged during a strike. These limitations can all be managed to one degree or another, but they are limitations that must be considered when you attempt to employ the weapon in a thrusting manner.
You can hold a stick in each hand and then use the cord or chain to strike into or abrade against a target area. Holding both sticks would allow you, for example, to strike with the cord directly into the front of the throat. You might also use a similar thrusting motion to press an incoming punch or grab attempt downward or to the side.
Once the cord has been wrapped around any part of a person’s anatomy (wrist, leg, forearm, neck, etc.) then tremendous pressure can be applied by pressing the two free ends of the sticks toward one another.
The cord or chain can be used much like a sticky hand maneuver. This may cause the same effect as a stick hand, but it may also abrade the surface against which the cord is moving.
If your Nunchaku has a chain then you might hold both sticks in one hand and flick the weapon (similar to a Spider’s Flick) toward an opponent’s face such that the chain acts much like a whip. This can be quite effective with a chain but is less practical if your weapon is corded.
Uchi strikes involve using the weapon as though it were a club. This can be accomplished by holding both sticks in one hand and then swinging the weapon like you would swing a club. Such action might be effective but there is also a risk of dislodging the weapon from your hand since one or both sticks might shift and escape from your grip.
An alternate form of Uchi strike is to hold a stick in each hand while adopting a reverse grip with your striking hand. Holding the weapon very near the chain or cord will allow you to strike with the blunt end of the stick with substantial force. The downside of this is that the other arm must remain relatively close to the striking hand in order to facilitate the strike. This is neither impossible nor impractical, but it can present difficulties in some situations where your two hands must move in separate directions for some reason. You could release the grip on one of the sticks, but this will result in a loose stick that may move in a random and unpredictable manner.
Another Uchi strike can be initiated by wrapping your palm around the corded/chain end of one or both weapons. This makes it possible to now use a forearm strike to impart a powerful blow into a target.