Which thumb is the proper one to hit the space bar, the left or the right?

The right thumb. This is because the left thumb is more useful and important than the right. Think of it this way: If you were using a sword, would you want to be able to use your right hand or your left hand? All you would want to do is use your right hand, right? It’s the same with the thumb. The thumb on your right hand is the most important thumb because it’s the one you use for the space bar when typing, the most used key in typing.

It is also the thumb you can use to point with. By using your right thumb, you are preserving the thumb you are going to use for pointing, which is the left thumb. So by using your right thumb for the space bar and not your left, you are preserving the left thumb for pointing.

The thumb that is not the dominant hand should be used for the spacebar. It is because the spacebar is the only key which is not on the home row. It is positioned in the bottom left corner. Therefore, the thumb that does not reach the spacebar is the one that should be used to press it. The thumb that is used to press the spacebar is called “Ghost Thumb”. The reason is that it “ghosts” the base of the hand in the bottom left corner. This also makes it easier to type on the spacebar.