What is the average career length of a NHL hockey player?

5-15 years depending on how well they play, how old they were when they started playing and if they have had concussions or injurys.

An NHL hockey player if they were really good, started young, and have had no injurys or concussions (which is very unlikley) could play for like 25 years if they really wanted to.

Martin Brodeur from the New Jersey Devils is known to be the best goalie who has ever played the game has been in the NHL for 19 or 20 years, and he is showing no signs of retiring.