Now you may be wondering what I mean by a paid contract, I don't mean paying your kids to play just to force them to play. Rather as motivation to be as great as he/she can be and also to teach him to become a team player. I remember when I was younger my dad used to pay me 50 cents for every point I would score, and I will do similar for my kid (when I have kids someday). 

Here is how I would start with my kid, lets say my kid starts to play competitive at the age of 10 I would have the following stats as a reason for pay. 

Steal = $.10
Rebound = $.10
Assist = $.10 
Point = $.10
Win = $1

This will help the new Basketball player love the game and puts a competitive edge in their attitude which will not only make them win more game, but also make them want to improve their skills and want to win more. 

There are many different ways you can control what your kids spend this money on, you can say they can buy whatever they want or you can say what its for. I will personally be putting limits on what this money can be spent on. My limits will be saying that the money will be only spent on active equipment e.g. shoes, Basketballs, sweatbands, clothing, food, etc... Basically no video games.