The Knights stay at such a consistant level due to a couple of different things.
1 - they are run like a professional team.
This means not only do they have great management in place, but they also have great coaches and great facilities.
2 - good players want to play there, and so do their parents.
Pros know a pro set up. Not only do former pros stear their kids to the program great young players also want to learn from a former great.
(The Knights don't have this exclusively as many minor leage programs are run or owned by former nhl'ers)
3 - Smart management.
If they arn't going to compete top players are moved for good picks and those picks are used well. If they are goign to compete, players are identified and acquired at a good price.
4 - Luck
When you are drafting kids that are 15 you never know how they are going to turn out. Most players that are drafted in the nhl are finished growing up but will still fill out so there is a good idea about how big a player will get. Most 15 year olds arn't anywhere near their full size. How they deal with that growth, and weather or not they can keep their skills as they grow are great unknowns in the junior ranks. So the knights have gotten lucky in the sense that a lot of their players end up contributing. Good coaching plays a part in that, but doesn't completely account for things.
I have watched the knights for over 20 years, and they haven't always been consistant but for the past 10-12 years they have risen and stayed at a high level. I hope they can keep it up now that Dale is in the NHL, cuz it is entertaining to watch.