Twenty Years of NBA Draft Picks

This heatmap colors each player by VORP (Value over Replacement Player), which converts the BPM rate into an estimate of each player’s overall contribution to the team, measured vs. what a theoretical ‘replacement player’ would provide, where the ‘replacement player’ is defined as a player onminimum salary or not a normal vmember of a team’s rotation. A VORP of -20 is used for players that did not play enough minutes.

Original visualization by Russell Goldenberg at The Pudding.

First, we draw a thin rectangle, repeat it by each row of data, bind its x position to “Draft_Year”, and bind the y position to “Draft_Pick”. Let’s first make the x scale wider by dragging the axis handle. Since we want the first draft picks to appear on top, we need to flip the y axis. To do this, we can drag the axis handle past the starting point.

Next, we encode the fill color using “VORP”. Since the VORP values include both positive and negative numbers, Data Illustrateur chooses a diverging color scale by default. We then set the background color to black, and change the x axis' orientation to top. Finally, we change the axis and legend colors to light gray, so that they stand out from the dark background.