Predicting NBA Rookie Performance By Draft Position

Nate Silver (and others) have tracked how NBA draft position relates to total career performance, see for example this article. But what about first-year performance?

I pulled two sets of data from basketball-reference.com to answer this question:

• Rookie season Win Shares for all players from 2003 – 2014.
• Draft positions by year from 2004-2014.

I then merged them using Power Query and then created a pivot table to calculate the average number of rookie season “win shares” by draft position. You can download my Excel workbook here. Here is what I found:

The first pick in the draft averages nearly five Win Shares in his rookie season, and while the pattern is irregular, win shares decrease as we get deeper into the draft (duh). (The blip at the end is due to Isaiah Thomas, drafted by the Kings who promptly screwed up by letting him go.) I have drawn a logarithmic trendline which fits the data not-to-shabbily: R^2 of 0.7397. Obviously we could do much better if we considered additional factors related to the player (such as their college performance) and team (the strength of teammates playing the same position, who will compete with the rookie for playing time). Here are the averages for the first 30 draft positions:

Draft POSITION	Win Shares
1	4.96
2	2.69
3	2.96
4	4.14
5	2.23
6	1.84
7	3.36
8	1.68
9	2.59
10	1.52
11	0.84
12	1.51
13	1.48
14	1.36
15	1.64
16	1.19
17	2.37
18	1.02
19	0.71
20	1.09
21	1.74
22	2.14
23	1.54
24	2.29
25	0.98
26	1.23
27	1.08
28	0.40
29	0.54
30	0.94
31	0.79