How to train knife throwing
Do try to get practice as often as possible! Twice a week would be perfect, but you will learn it even if you don`t have that much time to spare.
To be in good shape for throwing, try to do 20-40 pushups every evening. In the beginning, your fingers will most likely be too weak, so try to get exercise with finger weights or springs until you feel that the knives leave the hand when you want them to.
Keep the training sessions short at first. After 15 minutes, your arms will get tired, and you loose your concentration. You will get very few sticks, and perhaps even adopt a bad knife throwing style!
Accuracy: Do not aim at a whole area, but a one specific point, e.g. an irregularity in the grain of the wood. Most likely you will notice that your knives do not stick in the target point, but in a specific direction beside it. Now it is easy, just move the point you are aiming at in your mind.
For the target point, you have some possibilities: really paint it on the wood, use playing cards or pieces of fabric. You can also make rings to throw into. Make sure to sprawl the little targets all over the target board, it will thank you by lasting longer, and you have more diversity for your practice throws. But leave an empty margin around your marks so that not too many knives miss the board.
To correct the distance to the target, you must know how the throwing knife rotates: If thrown from the handle, the blade will first go down. Such, if the knife sticks handle up, it rotated too much, meaning it has travelled too long because you stand too far away from the target. If it sticks handle down, you should move back. And seeing just the back of the handle, you can proudly call it a perfect stick.
Move only a few centimetres back or forth to find the right distance - only if the knife bangs against the target vertically, adjust the distance by two length of your foot.*
You should only change one parameter of the throw at a time (for example the distance or the grip). That way, you know why your knife suddenly doesn't stick any more.
Often, the throwing knives penetrate the wood deeply. To remove a knife from the target, move it up and down - like a lever - until it is loose enough. Always make the movement with the plane of the blade, and not sideways, or you risk breaking the blade! It's a good idea to get accustomed to supporting the target with your empty hand while pulling out your knives. That'll prevent some log round or even the whole target stand from falling towards you that one day when your throw planted a knife extra firmly.
If you feel comfortable throwing a full spin, you can go to the next distance (two spins at 5m). Small deviations in you throw suddenly become amplified, your knives will stick less frequently. If you are doing really bad at the further distance, go back to the previous one for some series of throws. You'll notice the target now looks bigger, and you are sticking better than before!
* A short look at the physics of adjusting the distance: If the throwing knife strikes the target vertically (handle pointing straight to the ground / the sky), it is off by a rotation of 90°. So we need to correct accordingly: With 2m per one full 360° rotation, the required delta in throwing distance is calculated at 200cm ∙ 90° / 360° = 50cm. Which means you have to go back or forth about two lengths of your foot to get the right distance to the target.