I searched the forums and I searched Google and couldn’t find any answer.
Football games are 60 minutes.
Hockey games are 60 minutes.
Soccer games are 90 minutes.
Basketball games are 48 minutes(NBA), or as low as 32 minutes(high school).
Why can’t basketball players play for 60 minutes? How was 48 (or 40 or 32) minutes decided on?
I’ll contribute that Dr. Naismith’s 12th rule (of 13) was that a basketball game was two 15 minute halves (with a sudden death overtime at the captain’s discretion (rule 13)). Not sure the history of how the game evolved over time in terms of time. 
Because if they were any longer than 48 minutes, you couldn’t fit them into a 3 hour time slot on network TV.
Sure you could. You’d just have to modify the rules that give you seemingly 25,000 timeouts, reset for the last two minutes that take 45 minutes to play.
So… it’s just arbitrary? I have to believe there’s some sort of reason, practical or no.
Kareem answered the question in Airplane
In American Football the ball is in play only about 15 minutes a game, so saying each game is 60 minutes long is not quite accurate.
At least in basketball ( NBA ) the players actually play for 48 minutes. Every second counts. When they are standing around waiting for a free throw to be shot for example, the clock is off.
Basketball games are shorter than other major sports, but the players are in a lot better shape than players in the other sports. If the clock is on, there is very little standing around in the NBA.
Tradition, of course.
College basketball had two halves. Currently they are 20 minutes.
When the NBA was formed, it was felt that the two halves would lead to too short an event (remember, college basketball had two games each time: JV and varsity). People didn’t want to pay for just 40 minutes of action (actually, the halves might even have been shorter back then). So the NBA decided that four 12-minute quarters would give a long enough game for the fans to be satisfied. It’s been that way ever since.
Kinda depends on how you define “better shape”. Basketball players probably have better cardio than some linemen, but NFL backs, receivers, and DBs do everything basketball players do while wearing heavier equipment and experiencing intentional violent contact. Fighters, whether boxing or MMA, are probably going to be in excellent condition when fighting.
True but they don’t play offense and defense (anymore.)
Soccer players might have the best conditioning. Not too many substitutions and they are running around the entire time.
And there’s a lot of standing around in the NHL while the clock is running?
No, but keep in mind the players are switching out constantly —there’s far less of that in basketball.
Hockey players change constantly because they full-out sprint for 40 seconds to a minute at a time. Basketball players don’t do that. That doesn’t make hockey players better or worse athletes than basketball players.
Yikes! That’s not my point —it’s just that, if we want to compare requirements of endurance, we need to keep in mind that hockey players switch out often. And yes, I know, they have to be in brilliant shape.
American sports, maybe. But soccer players make a mockery of this claim, and I wouldn’t be surprised if rugby players do as well. Basketball has way more substitions than soccer, soccer players run a much greater distance, and a soccer game is twice as long. (Average of 96 minutes, I would guess.)
That begs the question, though: Why 40 minutes? Every other sport seems to instinctively gravitate to an hour. Soccer shows us that conditioning isn’t a valid justification for a shorter game; was there something about the early versions that made a 60 minute game take too long or get boring or something? I mean before innovations like dribbling…
Well, James Naismith set up the first rules. He stipulated two fifteen-minute halves. The reasoning could have been anything, but most likely it had to do with the length of the gym period at the time. Two fifteen-minute halves with a two-minute break in between would allow you to fit a game into a 45-minute gym period.
Because each quarter is 12 minutes. 12 X 4 (number of quarters that make a whole game) = 48.
Some other number X 4 (number of quarters that make a whole game) not = 48.
The high school time length is the closest to the Naismith rules, they just split the game into 4 quarters instead of 2 halves. The next evenly divided number by 4 from 30 is 32, so you get 8 minute quarters. Why the split from 2 halves to 4 quarters? Probably gives the young players most opportunity to rest, would be my guess.
I’m guessing RealityChuck’s idea that both the college & pro games were lengthened to provide more value for the attending fans buck is closest to the truth. I’m sure someone decided along the way that 1 hour of sports entertainment just isn’t “enough”. A briskly played college game without TV timeouts and such probably clocks in at about 1:30. Two hours is something of a natural sweet spot in both fan attention and expectations and player endurance, probably.
Okay. The picture is starting to focus now. I guess it was just a progression of rule changes that led to 48 minutes being standardized, particularly in the pre-shot clock era. Now that I think of it I’ve heard stories of extremely low-scoring games (combined score less than 40) where one team made a couple of baskets then dribbled out the clock for the remainder of the game. I can see where that would make for a frustrating and boring game.
The development of the shot clock is well documented. It was developed by Danny Biasone, an owner of the Syracuse Nationals, who wanted to counteract the low-scoring game that was taking over. Teams in the lead would keep the ball forever in the second half (the NBA record for low score was in 1950, when the Pistons defeated the Lakers 19-18 (only four points were scored in the 4th quarter).
Biasone thought the slow pace was turning away fans, so he decided on a clock. He chose 24 seconds by determining that the average number of shots taken by both teams in a game was 120. He then divided this into the 48 minutes a game was played; this boiled down to 24 seconds.
The idea was later adopted at other levels.