When the pingpong balls came to a rest after Tuesday night’s NBA draft lottery, it was the end of an era for the league. Starting next season, the lottery’s distribution of odds based on team records will change — the first tweak to the system in 25 years. The jackpot-winning Phoenix Suns came out on top in this season’s historic tankfest, but from this moment on, the already-long odds of burning a franchise to the ground and building it back up will only get longer.
At least, that’s the effect the league is hoping the new lottery rules will have. How much of a difference will the changes to the lottery system really make, though? And will it be enough to discourage teams from tanking?
To work out some of the new math facing NBA teams, let’s turn to our draft-value chart, which measures the expected value over replacement player (VORP) that teams can expect out of a given draft pick in his first five pro seasons. (We’ll convert our chart from last summer to wins over replacement19 to better position the differences in a real-world context.)
As I wrote last year:
Early in the draft, the curve is steep. The average No. 2 pick is worth only about 80 percent as many VORP in his first five seasons as the average No. 1, and players only get less valuable from there.
This is part of why teams spend so much time and energy gunning for the worst record — and (until next year) the highest odds of picking No. 1. The chances of getting an impact player from the top pick are much better than at any other slot in the draft. But they’re not perfect; there’s a lot of luck involved in picking the player who’ll have the best career. Add in the extra randomness of getting the lottery balls to bounce your way, and the difference between the expected value of having the NBA’s worst record under the old system and next year’s new one is just 3.4 total wins over the first five years of a player’s career.
The new lottery will definitely change teams’ incentives in the right direction. It makes having a bottom-five record less valuable and improves the fortunes of teams in the rest of the lottery (particularly the Nos. 8 and 9 picks, which gain the most value under the new system). But it’s worth wondering if a change of about two-thirds of a win per season will really be enough to make a big dent in teams’ willingness to tank.
In fairness, the effect appears larger when you consider the outsize potential of top picks to become stars. Using WORP as a guide, there was about a 34 percent chance of landing an All Star-level player20 if a team had the worst record going into the 2018 lottery; those odds will fall to 27 percent under next year’s system. Seven percentage points doesn’t sound like a whole lot, but the NBA is so star-driven that any reduction in the probability of getting a franchise-altering player hurts. With the ability to get those kinds of players also increasing for teams who finish with, say, the league’s eighth-worst record, it should eventually help the anti-tanking effort by funneling more big stars to teams who don’t completely throw their seasons away.
So congratulations, Phoenix: You’re the last team who’ll take advantage of the old odds to help grab a potential star. The league’s changes might not be extreme enough to fully discourage teams from engaging in Sixers-style tear downs, but they’re a start. And after the race to the bottom that played out down the stretch of the 2017-18 season, such changes are more than welcome.
Check out our latest NBA predictions.