Draft Scores

Proposing a simple method to score a draft pick as a hit or miss.

Last week I examined the career value of every lottery pick from 1985 through 2009. The idea was to see what a franchise and its fans can expect when drafting from each of the 14 “lottery” slots. Today I’d like to present an idea for scoring draft picks.

I started by calculating the career value of every first and second round pick over the 30-draft span from 1985 through 2014. It was assumed that the first overall pick would produce the highest career value in a given draft, the second overall pick would produce the second-highest career value, etc. I then compared each player’s career value to the career value of every other player chosen in that draft. These expected and observed ranks were converted into a draft score using the following formula:

\(DraftScore=ln\left(\frac{ExpectedRank}{ObservedRank}\right)\)

There are, of course, numerous ways you could do this, but I like this method for several reasons:

1. The players aren’t saddled with unreasonable expectations simply based on their draft slot. All drafts aren’t created equal; some years the talent pool just isn’t very deep.

2. Players whose observed rank is higher than their expected rank will have a positive draft score, players whose observed rank is lower than their expected rank will have a negative draft score, and players whose observed rank equals their expected rank will have a draft score of zero.

3. Getting the player with the highest career value with the 11th overall pick (+2.40) is judged to be much more valuable than getting the player with the 15th-highest career value with the 25th pick (+0.51), even though each player finished 10 spots higher than expected.

As an example, here are the draft scores for the 13 lottery picks in the 1998 NBA Draft:

1. Michael Olowokandi, –3.00 (20th in career value)

2. Mike Bibby, –1.10 (6th)

3. Raef LaFrentz, –1.67 (3rd)

4. Antawn Jamison, 0.00 (4th)

5. Vince Carter, +0.51 (3rd)

6. Robert Traylor, –1.50 (27th)

7. Jason Williams, –0.45 (11th)

8. Larry Hughes, –0.12 (9th)

9. Dirk Nowitzki, +2.20 (1st)

10. Paul Pierce, +1.61 (2nd)

11. Bonzi Wells, –0.31 (15th)

12. Michael Doleac, –0.77 (26th)

13. Keon Clark, –0.48 (21st)

This method makes it possible to answer any number of draft-related questions, so the rest of this post will be presented in question-and-answer format. As you read, please keep in mind that the results below are for the 1985 through 2014 drafts only, not every draft in NBA history.