What exactly can teams count on when they make a draft pick? Well, unless a team releases or trades a player, they are under the organization's control after the draft for up to four years, the maximum length of a rookie contract. So really, when looking at draft steals, we should focus almost exclusively on the first four years of a player's career.
"Almost" is used because sometimes a player's first four seasons in the NBA aren't necessarily the four years that came directly after he was drafted.
As a result, I looked at the first four years of win-shares data for a player, as provided by Basketball-Reference.com. Win shares are an advanced basketball metric calculated so that one win share is exactly equal to one win provided by that player to his team's cause. It's the combination of offensive win shares and defensive win shares, a full breakdown of which can be found on this page, called "Calculating Win Shares."
Win shares are inherently flawed because they can't completely sum up a player's value, but it's the best number we have for turning overall value into a single metric that goes up based on both volume and quality.
Starting with the year 1982, I've looked at each and every single player drafted into the Association, tracking their draft position and the amount of win shares they produced in their first four seasons in the league. It is important to note that I only evaluated data through the 2009 draft because the players taken from 2010-2013 have not yet played out their first four seasons in the league.
After I had data for all 2,437 players drafted from 1982-2009, I took the average number of four-year win shares for each draft position and plotted them on a scatterplot (which you can see in the embedded picture, with draft position along the x-axis and four-year win shares along the y-axis).
Using a best-fit logistical regression, I found the following formula: Four-year win shares = -6.031* ln (draft position) + 25.388.
For the statistically inclined out there, that equation has a coefficient of determination (r^2) of 0.92083. For the non-statistically inclined, the equation fits ridiculously well.
Using this formula, we can plug in a number for draft position and have the formula show how many four-year win shares a player drafted there should be expected to produce. For example, the first overall pick of a draft should produce 25.388 Win Shares, while the 30th overall pick should produce 4.875.
With that data firmly established, we can tell exactly how much players have exceeded or failed to live up to the expectations associated with the slot in which they were drafted. That can be done by subtracting the expected win shares based on the draft position from the actual number of four-year win shares that players produced.
If the difference is positive, the player exceeded expectations by that much and was a bit of a steal. If the difference is negative, the player failed to live up to the expectations and was a bit of a bust.
Let's use Michael Jordan as an example, even though he didn't get drafted in the past 25 years.
Jordan was drafted third overall, so he should have been expected to produce 18.76 four-year win shares. The shooting guard actually produced 53.6 over the first four years of his career, meaning that the Chicago Bulls "stole" 34.84 four-year win shares when they drafted him. This was still a great pick, obviously.
In fact, it was the second-best since 1982.
It's important to realize exactly what we're looking at. As some of you may have realized, even No. 1 picks may be considered steals. Likewise, even non-lottery picks can be major busts if they perform poorly enough.
Because this article reveals the 50 biggest steals of the past 25 years, but players drafted from 2010-12 are not yet eligible, here you can find a list of recently drafted players who look like they could "earn" a spot on this list in the future.
- From 2010: Paul George
- From 2011: Kyrie Irving, Kawhi Leonard, Kenneth Faried, Jimmy Butler, Chandler Parsons, Isaiah Thomas
- From 2012: Damian Lillard, Jared Sullinger
Going forward, you'll find a few pieces of information on each slide. There's the typical description of where each player was drafted and by what team. Additionally, you'll find how many four-year win shares each player earned, as well as a brief player description.
Now, read on to find out the 50 biggest draft steals since the 1988 NBA draft. You will be surprised, especially if you don't remember that objectivity eliminates injuries and such from the list of excuses for a lack of performance.
Note: The above explanation is a modified version of what I wrote here.