Sometimes it's good drafting. Other times it's the luck of the draw.
But no matter how it happens, when a rookie has a fantastic start to a season, it's almost a bonus to any team.
You don't come into a season relying on your rookies to steal the show (unless you're the Edmonton Oilers), but when it happens, the team can only benefit.
And the GM looks like a genius.
This season through the first quarter, there have been plenty of rookies who have played great, but there are some who have played rather surprisingly.
It may be because they were drafted low and weren't expected to do much, or even make the team this year. Maybe, it's just a high pick playing more like a six-year veteran than a first-year kid.
With rookies playing so well, we are seeing the veterans either being pushed to the side, or pushed to play better or else suffer a demotion.
It's been fun so far.
Here are the top 15 rookies in the NHL in 2010-11.