- The first baskets were nailed to a gym balcony rail that happened to sit 10 feet off the floor.
- That was December 1891 in Springfield, Massachusetts. The height has not changed since.
- The NBA, WNBA, college and high school all play on a 10-foot rim.
- The NBA tested a 12-foot rim in one 1954 game. Shooting got worse and the idea was dropped.
In December 1891, James Naismith had a problem. He was a physical education instructor in Springfield, Massachusetts, with a restless class and a long winter ahead. He needed a game that could be played indoors.
He asked the building superintendent for two boxes to use as goals. The man came back with two peach baskets. Naismith nailed one to the lower rail of the gym balcony at each end of the floor. That rail was 10 feet up.
Nobody measured anything. Nobody argued about the number. It was simply where the balcony was.
The balcony left. The number stayed.
Within a few years the game had spread to gyms with no balcony at all. The baskets moved onto poles, and then onto backboards. Backboards arrived partly because fans sitting in the balcony kept reaching over the rail to swat shots away.
By then the rule books had written 10 feet down, and every new gym copied it. Almost everything else about the game has changed since. The peach basket became a metal rim with an open net. The shot clock arrived. So did the three-point line. The rim stayed where the balcony put it.
Nobody chose 10 feet. It was simply where the balcony was.
The court by the numbers
| Measurement | Imperial | Metric |
|---|---|---|
| Rim height | 10 ft | 3.05 m |
| Rim diameter | 18 in | 45.7 cm |
| Backboard | 6 ft x 3.5 ft | 1.83 m x 1.07 m |
| Free-throw line to backboard | 15 ft | 4.57 m |
| Three-point line, top of the arc | 23 ft 9 in | 7.24 m |
| Three-point line, corners | 22 ft | 6.71 m |
Has anyone tried raising it?
Yes. On March 7, 1954, the NBA had the Minneapolis Lakers and the Milwaukee Hawks play a regular-season game on 12-foot rims. The idea, pushed for years by Kansas coach Phog Allen, was to shrink the advantage of very tall players.
It did the opposite. The Lakers shot 28.6 percent and still won, 65-63. Shooting got worse for everyone, the tall players still controlled the rebounds, and the experiment ended after one night.
The idea comes back every few years, usually after a season full of highlight dunks. The answer is always the same. A higher rim punishes shooters more than it punishes height.
Why it will probably never change
Every court in the world is built around that number. So are millions of driveway hoops, school gyms and playgrounds. Move the rim and a century of records stops being comparable.
There is also the dunk. The play that fills highlight reels depends on a rim that the best athletes can only just rise above. Ten feet turned out to be a very good accident.