2011 Draft Similarity Scores
The NCAA’s deadline to withdraw from the NBA draft has passed and the field is now set. Frustrated with the amount of subjective analysis surrounding the draft, especially comparisons based mostly around physical appearance, I attempted last spring to create a statistical means for comparing draft prospects to draft prospects from previous seasons. Here is a little explanation of the impetus for this project:
For years, every guard with exceptional leaping ability was potentially the next Michael Jordan. Every long white player who can shoot is the next Larry Bird, Keith Van Horn or Adam Morrison; depending on the era. Although, in some parts of Rhode Island they’re referred to as the second coming of Austin Croshere. Every point guard from Gonzaga is the next John Stockton, every huge, awkward center is the next Greg Ostertag and every shot-blocking center with African roots is the next Dikembe Mutombo. These comparisons, based on skin color, position, the college they attended or one singular attribute, do a diservice to the players and fans alike.
The idea was to create an objective method for comparing players, instead of having to rely so heavily on subjective observation. I recognize that this is largely an over-reaction which creates its own set of problems. This system is based on college statistics, and just those from the season before the player was drafted. Therefore, it doesn’t capture potential, patterns of development, personality, or athleticism; besides how it is tangentially reflected in a player’s production. What these similarity scores are meant to identify are the players who produced at the most comparable level to each draft prospect. John Hollinger, of ESPN, and Kevin Pelton, of Basketball Prospectus, both have similar systems, which haven’t been released yet for this year’s draft. However, theirs compare draft prospects to NBA players and are much more valuable in predicting potential career arcs for each player. Mine is merely a snapshot - at this moment in time Player A’s college production is most similar to Player B’s.
I’ve changed my technique a little since last year. I’ve refined the statistical categories, as well as slightly changing the output. The categories I settled on this season are:
- Minutes per Game
- Points per 40 minutes
- Offensive Rebounds per 40 minutes
- Defensive Rebounds per 40 minutes
- Assists per 40 minutes
- Steals per 40 minutes
- Blocks per 40 minutes
- Personal Fouls per 40 minutes
- 2PT Field Goal Percentage
- 3PT Field Goal Percentage
- Free Throw Percentage
- Free Throw Attempts per 40 minutes
- 3PT Attempts per Field Goal Attempt
- Assists per Field Goal Attempt
- Pure Point Rating
- Percentage of Team’s Possessions Used
- Points per Possession
- Field Goal Attempts per Possession
- Turnovers per Possession
My database for comparison uses every collegiate player selected in the 1st Round of the draft going back to 2001. A few 2nd Round picks from last year’s draft are included as well. Each prospect for this year’s draft is compared to that set in each of the 21 categories. I took the absolute value of the standardized difference between each player’s performance in each category, and multiplied it by 10. That total is then subtracted from 1000. Each similarity score is then on a scale from 0-1000, 0 representing complete opposites, 1000 representing a perfect match. The technique was borrowed from this Basketball-Reference article. My system is not perfect, many of the comparisons are not as statistically close as I would have hoped, others are certainly head-scratching. As usual, I’ll take what I’ve learned and try to improve on it in the future.
For this year’s list of prospects I took the first 40 collegiate players listed in Draftexpress.com’s 2011 Mock Draft. The list is below. My plan is to create a separate page for each prospect showing the results. On each page you will find links to draft profiles, and a comically over-sized table showing the stats for the 10 most similar players. I will be populating the list below with links as the pages are finished. However, all the calculations are done and the spreadsheet can be accessed here. As always, feedback and comments are always welcome.