I remember this episode. Ross was basically depressed because this was the anniversary he and his ex-wife first consummated their physical relationship. She since left Ross to be with a woman. To cheer him up, Chandler took him to a hockey game. Ross at first refused, but when he got to the game and got into it, Chandler said to him, "see, buddy, that's all you need (to cheer up), a bunch of toothless guys hitting each other with sticks." Here, Chandler was just exaggerating how violent hockey is - so violent that the players are toothless from losing all their teeth getting hit in the face by the hockey sticks or the puck. Then moments later, a hockey puck ricocheted off the rink and hit Ross … right in the face!

anyone who plays football knows the speed of the puck it's same as if he would make a joke about "boxers' headache" :)

Hi Mark, The joke is making fun of hockey - as you can see here (http://www.greatesthockeylegends.com/2010/10/top-ten-hockeys-worst-teeth.html), hockey players lose teeth often sticks, pucks, or fists. Hockey is not as popular in the USA as baseball or basketball, which are both inferior sports, and so Americans often make fun of Hockey because it so much better than baseball or basketball (basketball was invented by a Canadian, James Naismith, but it was no good so Canada abandoned the sport and now has only one team in the NBA as a gesture of friendship). I hope that helps!

We would probably need to see the clip to help you out, at the very least know more of the conversation. The character of which you speak is known for somewhat subtle and wry humor and sarcasm, so it's hard to tell just from one line.