why do hockey players tap their sticks three times at the start of a game?

no pick-up hockey fans out there?

when you say "start of a game" you could mean 2 things:

1) start of a pick up game?

This is done because in a pick up game, there's usually no referee. Referees drop pucks. How do you drop a puck for a beginning game's faceoff fairly without a referee? ask a player on a side to drop it for you? Sure, but that player may have a bias to drop the puck favouring his teammate, so that idea is sometimes done, but rarely. Plus, with one of your players dropping the puck, it means he can't be in his position for the faceoff, which is a disadvantage, even if you drop the puck favouring your teammate's chances of winning the faceoff draw. No, instead, players on opposing teams off a faceoff tap their stick 3 times because it is a fairer way of dropping the puck between 2 competitors. Tap the ice, tap the opponent player's stick, tap the ice (2), tap the opponent player's stick, tap the ice (3), tap the opponent player's stick. now the opposing players treat the puck that was between them while the 3 taps have been going as 'live' (as in just dropped from a referee's hand) and the players go after the puck like it was dropped from a faceoff.

2) start of an NHL game?

no answer for you here. could be because most times hockey players bang their sticks on the ice because it is their way of clapping (they have gloves on, and that won't make enough noise for the player to sow his respect

Out of respect for our troops overseas? Please, as much as this is a nice thought, hockey players have been doing this long before troops were overseas, and they don't stop tapping their sticks when troops aren't overseas.

There is no specific reason why hockey players do this. They might do it after the national anthem is sung instead of an oh-so inconvenient clap. It might also be a superstition to a certain player, but in the hockey world it seems to be as thought about as skating...Not at all!

if you're talking about field hockey, they don't do it at the start anymore.. The only time they might do it is if a referee is unsure whos at fault for something so they do a 'drop ball' where they tap once then hit!!!

They banned it before becasue it was too dangerous! (and coins were invented to toss =) )

In respect for the man and women across seas and for the veterans in the country

To signal to the girl downstairs that they'd like to...

No, wait, that was Tony Orlando in that song. Sorry.