One of these is a weapon, one of these is not.
(Hint: it’s the nunchaku. That’s the weapon.)
The nunchaku is essentially a short flail. It generates a lot of force on rotation and the loose chain allows for you to carry the full force of the swing into an opponent. A single swing can break your face. The nunchaku does so with a lot less effort and windup on the part of the wielder that you’d need when using a bat, while being far more effective.
Imagine for a moment another person walking up to you in a heavy trench coat. They reach inside and out comes the nunchaku, with a single flick of their wrist they’ve sent a bar of pure steel whipping across your face.
That’s the amount of time they needed to break your jaw.
Now, instead of being finished like one would with a bat, the nunchaku is spinning on that chain. The recoil it has when it hits an object allows the wielder to easily transition into building greater force. A strike across puts it in position to hit you again, this time with greater force than it did on the first strike. They strike diagonally across your head, specifically aiming for your temple, which now will have killed you.
Two strikes for the price of one, while maintaining a clean stance, all with a lot less effort than it takes to swing a bat.
Bats are designed to hit baseballs and all the force ends up in the tip, if you want to be successful when you hit someone else with them then you have to connect with that tip. Bats are ridiculously easy to stop on the basis of two things:
1) To take full advantage of the swing, they require the full wind up. This is a huge telegraphed motion. Any heavily telegraphed body movement is easy to dodge.
2) You either step back when they swing and let it go past, then go forward in the opening left available or you just keep going forward and let the mid point of the bat hit your ribs. It’ll hurt some, but that isn’t where the weighted point behind the force is. Their hands are tied up. So, you hit them.
The nunchaku is used in a single hand, leaving one free for defense. It can be switched between different hands to great effect. A trained wielder is usually ambidextrous, allowing them to switch off as needed or carry two if they feel like it. They use their body to catch, cushion, and redirect the strikes.
The nunchaku’s body is generally made of wood or metal. It’s extraordinarily easy to conceal, which is why it is banned in several states. It is an exceptionally good weapon if you know how to use it and can be a very painful weapon (for you) if you don’t.
It will give you many more options in strike pattern than a bat, opening up the whole of the human body, without loss of defense.
It’s fast and builds momentum faster, in fact, than the bat due to the chain.
It is easier to use than a bat, carries less associated risk than a bat, and allows for better defense. Bruce Lee made a career using the nunchaku on film which was considered by and large too risky because you cannot totally control how hard you strike the other person.
It’s not a weapon you carry if you intend to avoid cracking open another person’s head like an egg.
When asking yourself: which is the more effective weapon?
Always ask yourself: which one is the weapon?
In absence of all other context, that’s probably the most effective one.