The shot clock, international rules, and decision making

During the women’s Final Four and WBCA convention, I spoke to several college coaches about potential rule changes in NCAA basketball. The most prominent rule change would be a change in the shot clock to 24 seconds, which led me into more discussions of the shot clock. 

I have written about the shot clock for high school basketball previously (here, here, and here). The NCAA change would be more subtle, as the clock would move from 30 seconds to 24 s to align with FIBA and the NBA.

In my interviews, coaches made good arguments against the shortening of the clock: Villanova head coach Harry Perretta said:

“A shorter shot clock does not help the game generally because the shorter shot clock does not allow for multiple styles of play.”

That is my lone objection to the shot clock, just as I worry that analytics will lead to every team playing exactly the same style in the NBA.

Another coach argued that a shorter shot clock does not guarantee a more attractive game, and pointed to the WNBA, which has a 24 s shot clock, but has not captured a large audience. I agree that higher scoring games do not transfer to higher quality games or excitement, an argument that I made with regards to the high-school shot clock.

The argument that was popular, and which I do not understand, is that a shorter shot clock leads to more bad shots and hurried decisions. This argument, which coaches seemed not to question, actually is not supported by statistics.

A study in men’s basketball examined the effect of possession duration on shooting efficiency. Offensive possessions are affected by the manner in which a team acquires the ball, but after 10 seconds, the differences disappear: A steal tends to lead to higher offensive efficiency than a possession that starts with the offense inbounding the basketball. 

After eliminating the possessions that took less than 10 seconds, primarily transition possessions which are more efficient than half-court possessions, the study found:

The average effective field goal percentage on initial shots between 10 and 15 seconds is 49%, between 25 and 30 seconds is 45%, and after 30 seconds is 41%.

The same trend has been found in the NBA: Offenses are more efficient earlier in the shot clock.

Therefore, statistics suggest that shooting more quickly does not lead to poor shots or hurried decisions. Of course, a 24 s shot clock would be different than a 35 s shot clock, but there is little to suggest that a shorter clock would lead automatically to worse shooting or more turnovers (on a per possession basis).

Furthermore, several times during the weekend, coaches lamented the U.S. system and lack of fundamentals, and pointed to European players as the model. Of course, these are players who grow up with a 24 s shot clock.

In NCAA men’s basketball, especially, teams dribble around for 10-15 seconds anyway. They waste time. Is that what we need a longer shot clock for: To enable teams to dribble around the top and waste more time?

Furthermore, many teams shoot against the shot clock with a 35 s shot clock because they pass up good shots early in the clock. With a 24 s shot clock, they would be less likely to pass up these early shots. In the NBA, teams tend to shoot the first good shot because it is hard to create two good shots in one possession against a good defense. NCAA teams are more patient, but they end up playing against the shot clock, which leads to worse shots.

As I commented during one of the NCAA Tournament games, the shot selection could not be any worse with a shorter clock than it is presently. In men’s and women’s basketball, there are so many bad shots attempted.

I favor a 24 s shot clock because I have coached in Europe, and I am used to it, just as college coaches are more familiar and comfortable with the 30 or 35 second clocks. I can appreciate Perretta’s argument about styles of play, and I agree that higher scoring games are not necessarily better games.

However, I disagree that a shot clock or a shorter shot clock leads to worse decision-making and bad shots. If that is true, why do teams fastbreak? Aren’t the players more inclined to make hurried decisions and take bad shots in transition than the half-court? Shouldn’t all teams walk up the court to avoid these reckless possessions?

Of course not. In the first year, players may take some time to adjust, but they will adjust. They will learn. A shorter clock does not cause bad shots or hurried decisions any more than a longer clock ensures good shots and decisions.

Personally, I believe the men’s game needs a shorter clock, but I don’t have strong opinions on the 30 s clock vs. the 24 s clock. However, when the arguments are made, I hope the coaches reconsider the idea that a shorter clock will lead automatically to worse shots and decisions. It won’t. Actually, it may improve shooting and decision-making, as demonstrated by everyone’s favorite model of fundamentals, European basketball.

By Brian McCormick, PhD
Director of Coaching, Playmakers Basketball Development League
Author, The 21st Century Basketball Practice and Fake Fundamentals

3 thoughts on “The shot clock, international rules, and decision making

  • I have to challenge you on the conclusion you draw from the data:
    The average effective field goal percentage on initial shots between 10 and 15 seconds is 49%, between 25 and 30 seconds is 45%, and after 30 seconds is 41%.
    There is another possible explanation: teams are looking for a “good shot” but the definition of a good shot changes with respect to time left on the shot clock. In the first 10s, i.e. transition, open shots at the rim and open catch and shoot jumpers are what teams consider a good shot. As teams get into their half-court offenses, the definition of a “good look” is expanded to include an open shot coming off a screen, a shot from the post or a contested shot at the rim. As an offense gets even deeper into the shot clock, lower percentage shots are considered acceptable until in the last second, any shot is a “good shot.”
    I would interpret your data as implying offenses are more selective early and therefore shoot a higher percentage. Shooting percentage is directly proportional to the amount of time remaining on the clock (more time left -> better shots), not inversely proportional to the amount of time that has passed (less time spent -> better shots). This in turn could lead to the conclusion that the shot clock needs to be lengthened, not shortened.
    I wholeheartedly agree that one guy dribbling for 90% of the shot clock is not good for anybody and if that’s what teams insist on doing then by all means, shorten the amount of time they can do that. But if teams are working for a high percentage shot (passing up an open shot for a good shot and passing up a good shot for a great shot) then shortening the clock makes that harder.
    Thanks for your work. I really enjoy reading it, even if I don’t completely agree, you make me think. keep up the good work.

  • Mike:
    I agree with your analysis. My point is that worse shots and hurried decisions would not be an automatic outcome of a shorter clock.

    I see many teams pass up good shot trying to get a great shot only to take a bad shot. with a shorter clock, I think that they shoot the good shot, which is better than the bad shot, even if it means missing out on the occasional great shot.

    I also believe that players and coaches would adapt, which again returns to my overall premise: A shorter clock will not CAUSE worse shots and hurried decisions. Heck, some offenses – the dribble drive motion – were created specifically to shoot quickly to reduce potential turnovers! My SABA system is designed for a quicker style of play; the goal is never to allow the defense to get set. When teams take their time, they play against a set defense, and offense is always more efficient against a defense that is not set versus one that is set. When playing with the 35 s shot clock or no shot clock in HS, teams hold the ball; they do not take advantage of small openings. They make offense harder. I guess that I am arguing that players and coaches would adapt to the shorter clock and learn to take advantage of these small advantages, making the game easier.

    Also, in my experience, my players in Europe were more relaxed in the last 5 seconds of a shot clock because they grow up with a 24 s shot clock and play many more possessions against the end of the clock. It’s no big deal. In the U.S., players rush with 5-6 seconds left on the clock, which is a ton of time. Again, I think players would adapt with more experience playing at the end of the shot clock, as would happen with a shorter clock.

    Also, the same basic statistics are true in the NBA, I just could not find relevant articles quickly.

    Finally, the same coaches who argue against a shorter clock tell me that players from Europe are more skilled, make better decisions, etc. These players develop and play with a 24 s shot clock. I have had emails from coaches in Canada and Europe telling me that their players struggle to adjust in the U.S. because the shot clock is so long (men’s players, not women’s).

    Anyway, if the players who are more skilled develop with a shorter clock, why do we believe that U.S. players would get worse with a shorter shot clock?

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