Soccer/football is the most watched contact sport.

No it is not. But then again, it is. Depends on what your definition of "contact sport" is.

In most cases, ping pong is not a contact sport for it contains no actual physical contact between the players as you would see in hockey or football (which are full contact, or collision, sports).

According to another definition, ping pong, in a way, is a contact sports because there is physical contact between the player and the ball (when you go to serve the ball, you are holding it. This is considered contact between player and object).

it is a contact force

You can lose you firmly fixed teeth in a contact sport

A non-contact sport is a sport where the players do not come into contact with one another at all. They are separated. Non-contact sports include swimming, bowling, volleyball, skiing, tennis, etc.