Randomness and Skill Development
Stephen Curry, who nearly everyone has anointed as the greatest shooter on earth during this season and its playoffs, shot 2 for 15 from the three-point line last night. does his performance change anything?No.The below is a tweet based on an article about hockey. Therefore, it is not automatically generalizable to basketball, so 223 is not exact. However, the theme of the tweet is the same: There is some large number of shots required to eliminate random fluctuation before we make an evaluation or draw a conclusion on one's shooting percentages.
It takes ~223 shots before the effect of skill outweighs random variation in shooting pct%, per @DTMAboutHeart - http://t.co/7slASpNOKe
— Rob Vollman (@robvollmanNHL) June 6, 2015
Therefore, Curry's shooting throughout the season - 44% from the three-point line - is far more indicative of his shooting than one single game of 15 shots.This is important to remember when we examine improvement. If I work with a 53% three-point shooter, and he makes 9 of his next 10 shots, I did not fix his shot. He is not a 90% free-throw shooter now. The sample size is too small. Unfortunately, many coaches will use a small sample size to demonstrate their brilliance and convince others that they are masters of their craft.They may be. They may be the best at what the do. However, 10 shots is not proof. 100 shots is not proof. Is 223 enough? I don't know. I don't know the exact number, but there is a number that would reduce the random fluctuations and provide a more robust account of one's shooting.The goal, in training, is not a quick fix. The goal is long term improvement and performance. Remember that next time there is an advertisement for a clinic or workout that is guaranteed to do more in one workout than your high school coach did in 3 years or one that offers unrealistic improvement in a ridiculously short amount of time.Just as 15 shots does not prove that Curry is now a bad shooter, one workout or 100 shots will not demonstrate that a player has improved immensely.By Brian McCormick, PhDDirector of Coaching, Playmakers Basketball Development LeagueAuthor, The 21st Century Basketball Practice and Fake Fundamentals