History

• Naismith was inspired to affix the baskets up over the player's heads by a childhood game called duck-on-a-rock. It called for players to throw rocks at a target rock on top of another higher rock in an attempt to dislodge it.
  
  

Reasons for Rim Height

• Naismith placed the peach baskets used as the first basketball goals at a height of 10 feet because the railing around the gallery above the gym happened to be 10 feet off the floor. That's according to Naismith's own handwritten notes after he watched the first game.
  
  

Function

• Basketball goals include a backboard, a rim, and a net. The official NBA/NCAA rules for goals state that the top of the rim must be exactly 10 feet above the floor. The rim must be 18 inches in inside diameter. The rim must have a white-colored nylon between 15 and 18 inches in length. It must be no less than 30 thread and no thicker than 120 thread and must slightly check the ball's momentum as it passes through the net.
  
  

Possible Changes

• The game's continued popularity has proven Naismith correct in his choice of basket height. Changes have been proposed many times, but have never been implemented. Lowering the basket would make scoring too easy, and reduce the emphasis on skill. Raising the basket would lower scoring, and reduce dunking, one of the most exciting plays in the game.
  
  

Considerations

• Sometimes basketball rim heights are lowered in leagues or situations for younger or disabled players. These heights are dictated by individual leagues and organizations, and no strict, international or national rules exist to govern these modifications to the basic 10 foot rim height.