Shown in the chart is the NBA talent distribution across positions. There are five colored histograms for the five simple positions: point guard- blue, shooting guard- red, small forward- green, power forward- purple, and center- neon. Poor performances are to the left, great performances are to the right.
The data set is 13 years of wins produced evaluations (WP48) and comes from Wages of Wins. Each data value is a measurement made on a player at the end of a season.
The first thing that struck me was shooting guards don’t show up at the top. In the past 13 years, we haven’t had a player achieve a WP48 > 0.300 season at shooting guard. Outside shooters are valuable, but the superstar producers have been the big men and the ball handlers.
The big men have the highest variance in performance. I’m not sure whether talent evaluation gets blinded by the height, or it’s rational to let poor performing big men play. Based on how coaches allocate minutes, it’s probably the former.
The overall distribution isn’t symmetric; it’s skew right. There are fewer terrible annual performances than excellent annual performances. The average WP48 is higher than the median.
The skew and the disparity in the front court suggest we’re looking at a visual representation of the short supply of tall people.
Something Josh and Ari have been bringing up in the comments section is the cost of a bad player. A player with a WP48 of 0.050 is still technically winning you games. However, they are winning at a slower rate than average. This means in a race to win the most games by the time you play 82, you’re at a handicap.
So bad players not only hurt you in that they keep you from winning, but also in that they keep other good players from playing. As Josh points out, the chart skews to the right. There is no excuse to have a non-rookie player putting up negative wins on your team. We could even argue that it’s questionable to have below average players. It’s hard to get stars but Josh is showing that there’s a ton of talent in the middle in the NBA.