How Effective is Tanking?
In the wake of Sam Hinkie’s resignation as GM of the Philadelphia 76ers, there has been a lot of reflection about the effectiveness of his aggressive strategy. First of all, this is pretty unfair on Hinkie, because the job isn’t done yet – it’s about now that the 76ers land themselves a star in Brandon Ingram or Ben Simmons, and use that to lure a free agent and start to climb their way back to the top, but that’s just an aside. As a result of this, a lot of subsequent discussion has followed about the effectiveness of tanking in general. The most oft-used strategy for breaking this down is a lot of anecdotal, team-by-team evidence. Analysts will point to the Warriors as an example of how to win a championship without a number one pick, and their debating opponents will immediately fire back with the half-dozen championships won by number 1 picks in LeBron and Duncan in recent NBA history. After listening to this debate from both sides of the argument for a few days, I started brooding and pondering, and eventually decided I should investigate with some rigorous statistical analysis that removes the element of ambiguity.
Before I get into the research I conducted, I’ll just lay some groundwork for this discussion. Right off the bat, I’ll ask the question: “Which teams haven’t been bad in the past 8 years?” – the answer is a list of 6 teams, give or take: the Spurs, Rockets, Bulls, Mavs, Heat and Blazers. That’s 6 out of 30 teams in the NBA, so when someone says “x team bottomed out that year, got this player and is now a contender” the overwhelming likelihood is that any team has bottomed out. It’s not fair to point out that the Clippers sucked and got Griffin and now they’re good, when in reality every team has been bad at least once. Also the Clippers were terrible for a long time, a fact I know from experience, so eventually they were going to land a star. It fails to consider all the teams that bottomed out and haven’t picked up any talent to lift them into contending status (think Kings, Suns, Knicks, Pelicans, Timberwolves, Magic). So let’s look at this topic analytically, and develop some measure of a player’s likelihood of winning a championship.
The first relationship I thought I should explore is draft position vs win shares. If tanking works, we should see a lot of the win shares going in the first handful of picks. I thought it would be important to set up my timeframe beforehand, because everyone’s favourite activity is taking a statistic and playing with the specifics until it suits your point of view. I chose the 1994 draft as the earliest draft to consider, because it was the first one to look like the draft we have today, with a distributed lottery and (almost) 30 teams. It also gives a good 22 year timespan for any anomalies to be ironed out, there’s nothing worse than a small sample size. It’s also the year of the Glenn Robinson draft, so I wasn’t just going to cut him out to favour an anti-tanking stance, and it’s 1 year before the draft of Kevin Garnett, the earliest active player drafted.
I chose win shares as the statistic as it is the best advanced stat out there for success of a player. The player with the most win shares is Kareem Abdul-Jabbar, because he created a lot of wins over a long period of time. Jordan is 4th due to his career being shorter than Wilt and Malone before him, but his win shares per 48 minutes is the best of all time. The career win shares list can be found here <http://www.basketball-reference.com/leaders/ws_career.html> and I think you’ll agree it’s a good indicator of a player’s likelihood to win championships, seeing as winning is the point of basketball. You might be put off by the fact that MJ isn’t first, but if you want to maximise championships, longevity is a very important factor. You might also point to players like Chris Paul or Charles Barkley, who have plenty of win shares but no championships. Maybe there’s something to that, and pure win shares isn’t everything, but the most likely explanation for that is just plain bad luck, given how difficult it is to win a championship each year, even for the best team.
I took the win shares stat for every player drafted since 1994, and slotted them into draft position. I then graphed the total win shares from each draft spot since 1994 and got this:
Clearly, you can see that the win shares are pushed towards the front of the draft. Highlighting the top 10 win share contributors since 1994 shows that, with the exception of Kobe Bryant, they all went in the first 10 picks. The most important thing to take from this graph is that the advantage of having the number 1 pick isn’t that great, the dropoff from 1 to 5 isn’t great, and neither is it from 1 to 10. The other important thing to learn is that a lot of wins go well after the lottery. You’re by no means missing out of you don’t have a high lottery pick.
Obviously there is a lot of noise in this graph, and another way of looking at this data helps eliminate the bumpiness. This graph takes the cumulative total of win shares taken after a certain pick. Think of it as the amount of win shares already taken if you pick at a certain position.
You can clearly see from this graph that a quarter of the wins available in a draft will go within the first 5 picks, and the next quarter will go in picks 6-12. Almost 80% of the wins will be gone by the end of the first round, so about 30% of the win shares are still available to non-lottery teams every draft.
It’s also interesting to look at the median win shares for each pick. Median is the middle score in a set, so this value is useful for eliminating players who far exceed expectations or are complete busts, and is probably a better indicator of the most likely player you would expect to receive from a specific spot.
It backs up the observation that you’ll find the best players at the top of the draft, but there’s still some nice players to be found at the end of the lottery and smattered throughout the end of the first round. Interestingly enough, your median 3rd pick will contribute more wins than your median 1st pick. If I were to wager a guess, I’d say that this is because in addition to generational talent being taken at #1, you also get a lot of boom or bust players that eventually bust, think Michael Olowokandi, Kwame Brown, Andrea Bargnani or Greg Oden.
So, what can we learn from the relationship between win shares and draft pick?
– the best players generally go at the top of the draft (it’s comforting to know that NBA GMs aren’t just rolling dice to determine their pick)
– there are plenty of wins to be found outside of the number 1 pick, and still plenty outside of a top 5 pick.
– you won’t find a good player with the 6th pick, ever. Seriously, if anyone can suggest a reason why the 6th pick is so significantly worse than all the surrounding picks, let me know, because it’s so much worse that it almost can’t be chance.
This relationship would suggest that if you can get the number 1 pick, that’s the best place to find a superstar, and settling for the 2-5 pick isn’t a bad substitute either. That being said, there are plenty of players to be found outside of the top 5 picks. So after one relationship, I’d say it’s about 55/45 in favour of tanking. But this relationship is by no means the end of the story.
While this is a good indicator of where the talent comes from in a draft, maybe it’s not the best indicator of championships, because as everyone knows, you need all-stars to win championships, there’s only 5 players on the court so your talent needs to be condensed to win championships. So the logical next step is to look at where championships come from.
This is a much harder relationship to investigate than it might initially seem, for a few reasons. First of all, simply finding out how many championships a player has won isn’t as easy as it might seem. It’s not one of the key stats at the top of a player profile, and it’s certainly not a column in a draft summary table. Even if it were easily sourced, that wouldn’t be the most practical way to do things, because not all rings are earned evenly. Purely by championships, Robert Horry is a better player than Dirk Nowitzki, but not a single person who knows how to pronounce Nowitzki would take Horry over Dirk. Therefore, we need a better measure of championships won by a player at a certain draft position.
My solution was to partition each championship into weighted shares based on each player’s contribution to the team that season. The best way to split up players was by win shares, so every player on the roster of a championship team was credited with a championship share. Take LeBron, who had 14.5 win shares in the 2011-12 season, out of the heat’s combined 48.1 win shares. LeBron is credited with 14.5/48.1 championships for that season. This gives most of the credit to the key players on the roster without neglecting role players who are nevertheless essential to a championship team. The timespan was again any player drafted since 1994.
The result of breaking up these championship shares by pick position looks like so:
What you get is a more noisy version of the graph we produced by looking at win shares. In one aspect that’s good, because it shows that win shares was probably a good indicator of likelihood to win a championship. But in another aspect, it makes it difficult to try and gain any insight from the data. Let’s start with the bumps. I would say that there are 5 pick positions which can be called bumps in the data. Pick 1, 5, 13, 28 and 57. Pick 1 can be attributed to two players, Tim Duncan and LeBron James, with sprinklings of Glenn Robinson and Andrew Bogut. Pick 5 is a mix of Dwyane Wade, Ray Allen and Kevin Garnett. Pick 13, 28 and 57 can be attributed almost solely to Kobe Bryant, Tony Parker and Manu Ginobili respectively. If we take into account these factors, we can see a similar trend to the previous graph, that a lot of the talent goes at the top of the draft, but there’s still plenty left by the end of the lottery and even an entire half a championship left at the 57th pick.
Looking at the cumulative total tells the same story, where we see roughly half of the championships are taken by halfway through the first round, and the rest is spread out over the following round and a half. Taking a look at the players responsible for the bumps, it needs to be noted that, with the exception of LeBron James, Kevin Garnett and Ray Allen, all of these players were drafted to excellent teams that were already title contenders. The three exceptions all moved to other teams in pursuit of a championship, and earned their chips there.
So the lesson to be learnt from this graph is that nba championships are as much a product of the team you are drafted to as your inherent ability as a basketball player. This would suggest that having a good team environment is essential to growing your talents as a rookie in the NBA. Would Manu Ginobili have created 0.5 championships in his career and won 4 in total were he to have been drafted 1 pick earlier to the Warriors? Almost certainly not, without Pop and Duncan he probably would never have won a title. Would Kobe Bryant have earned an entire championship share and 5 rings in total were he to have not been traded on the day of the trade to the Lakers and instead played for the Hornets? Full respect for Kobe, but probably not without Shaq and Phil Jackson and later Pau Gasol.
So the conclusion from this relationship is that the make-up and quality of the team is critical to a player’s success. This skews the argument heavily in favour of an anti-tanking stance, probably at about 75-25 in favour of not tanking. But this data was based off an admittedly small sample size, there’s another piece of analysis that would be very helpful to evaluate effectiveness of tanking.
One way of taking a broader look at the effectiveness of tanking is to stop looking at all of the individual players taken at specific spots, which can be affected by single players who just buck the trend, and instead look at the future success of teams who pick at particular spots. So for the next analytical look at tanking, I charted pick position against the subsequent success of the team for the next 8 years. I chose 8 years because it is a long time, about the length of a player’s first two contracts, and a good length of tenure for a GM to turn around a failing franchise. So take the 1994 draft, where the Bucks picked first. I took their average win percentage for the next 8 years and put that into the number 1 pick data. The next year, the Warriors had the number 1 pick, so I took their win percentage for the next 8 years and added that to the number 1 pick data. After repeating this for every first round pick in the NBA since 1994, I developed a graph of team pick position vs subsequent team success, which looked like so:
(aside: I removed the second pick for a team that had multiple first round picks, as I didn’t want the data to be affected by duplication)
The only conclusion that can be drawn from this graph is that it makes almost no difference, the pick positions that perform the worst aren’t that far displaced from the teams that perform the best, excluding some outliers. This is a good sign for the NBA in general, since the point of the draft from a league perspective is to level the playing field, so it’s good that everyone experiences regression to the mean. It’s also worth observing that picking in the middle of the draft, in the so-called no-man’s-land of the NBA, appears to net you a better win% over time than any of the picks further up the draft, with the exception of the number 1 pick.
Additionally, there are no better results than if you can get yourself into a pick right at the end of the draft by being a pretty good team in the first place. So the conclusion here is the better you are, the better your win% will be in the future, unless you can land the #1 pick in the draft. If you tank and don’t get the number 1, you’ll end up in that 2-5 zone which results in the worst records of all picks. However, thanks to the lottery, the odds of getting the number 1 pick if you’re the worst team in the league are only 25%. This more than eliminates the incentive to get the number 1 pick, because it’s not automatic, even if you do suck, and if you win the lottery for second place you’re just stuck in a terrible place anyway.
The good thing about this model is that it isn’t biased by all of the randomness associated with players once they enter the league. This model accounts for the fact that a player might go searching for a new team in free agency, or that they get injured, and account for the fact that to get the number 1 pick, you need to be a bad team to begin with. When factoring in the effectiveness of tanking, you need to consider the fact that if you do land a superstar, they might not want to play for you (see LeBron). And look at the blip at the number 1 pick, it still doesn’t reach above the .500 mark! The only reason that bar is any higher than the ones around it is because of a few guys.
There’s one team that won 70% of their games after the number 1 pick – the spurs (if you’ve got Gregg Popovich as your coach, you can do it. Otherwise, no chance), and only 4 teams that won more that 52% of their games after the number 1 pick. Out of 14 drafts considered, there’s a 4 in 14 chance that you’ll get a player that turns your franchise around. So if you can be so bad that you’re the worst team in the league, you have a 25% chance of getting the number 1 pick (the only one that’s worth getting as can be seen from this graph). And after that, you’ve still only got a 28.6% (4 in 14) chance of that #1 pick being a player that will turn your franchise around. So if you’re the worst team in the league at the end of a given season there’s a 7.1% chance that you’ll become a +.500 team as a result. In other words, don’t bother tanking.
After Part 3, let’s say I’m now fairly in favour of not tanking.
Regardless, let’s soldier on further and see if we can dive deeper and gather a defense of tanking! That last relationship still doesn’t truly get to the roots of the issue, because win% is one thing, but the whole point of tanking is to win The Larry O’Brien Trophy, the true mark of a team’s success. (aside: if it means being like the 76ers for 3 years, and being a disgrace to the NBA and compromising the integrity of the league and turning people off being fans of your team, I don’t think it’s worth it to win one trophy, vs being a consistently respectable organisation) So let’s see if we can go one step further and instead look at the subsequent championships after picking at a certain pick. Luckily for me, it only took subbing in the championship winner each year to my spreadsheet instead of wins to get me that data. So let’s have a look at exactly the same process but chips instead of wins.
That’s pretty depressing for anyone with the number 1 pick, let’s be honest. Oh and by the way, if you’re still saying “but it’s still be best of a lot of inefficient strategies” if I take away 1 draft, the 1997 draft that saw Tim Duncan go to the Spurs, there is not a single team that has turned a number 1 pick into a championship in the 8 years following their selection. None. So tanking: not looking good.
Okay, this sample size isn’t huge, there have only been about 20 championships in this whole time frame, so let’s see if we can pad all the numbers up a little bit, flesh things out. Conference titles. Everyone agrees if you make it to the dance you’re in with a good shot.
Well, that hasn’t helped the case of the number 1 pick at all. Again, if you take out Tim Duncan, that line goes down some more and it’s almost no better than the next few picks all after it. So the case for the number 1 pick being a boom or bust strategy that could land you a championship is in a shambles.
So, after looking at all of those independent pieces of data and formulating a conclusion, I’ll enunciate them here. It’s pretty clear that tanking has worked once, the 1997 draft to select Tim Duncan. One time. Other times, it’s been effective at picking up stars, like LeBron James. But still no championships. So in the last 20 years, tanking has worked once, and you know why it worked? Because a humble, low-ego, super-talented player entered the league onto the roster of one of the best coaches in NBA history, put his head down and learnt and practiced and grew into one of the best power forwards of all time. He also landed on a roster that had some really good pieces and a former number 1 pick already there.
When the spurs got Duncan, it was a 1 time deal, they were bad for a single year thanks to injuries, lucked into Duncan and never looked back. So what we can learn from the one time tanking worked is not that tanking works, but instead that if you’re one of the best coaches in NBA history, you can make it work. But what of players like Kobe Bryant, Paul Pierce, Kevin Garnett? Well it’s pretty clear that the reason they were successful is because of a smart GM who saw their talent and landed an absolute gem later in the draft. We saw it work with the Spurs twice, when they drafted Tony Parker and Manu Ginobili with the 28th and 57th picks respectively in their own draft classes. Kobe and Pierce were also drafted to historically good franchises, and Garnett won his titles with one of those historic franchises.
I think the biggest flaw in thinking for those who expound tanking is a big assumption about the talent coming out of a draft. They assume that LeBron was a board-eating, dime-dropping, muscle-machine MVP when he was drafted, but in fact it took him years to develop the skills to be the player he is today. What he was, was a hard worker and hyper-dedicated. Duncan wasn’t drafted as one of the most skillful, graceful post players of all time. He was a hard worker, and extremely humble. See the same for every other transcendental talent, they got where they are because of hard work that continued into the NBA. If Duncan were to be drafted to the Sixers in this year’s draft as the lanky 21 year old he was in 1997 – without the help of David Robinson and Gregg Popovich – he wouldn’t win 5 titles. Straight up, he wouldn’t. Coaches and GMs win Championships. Let me phrase that another way, good teams win Championships. Good teams don’t lose on purpose. Don’t lose on purpose. Don’t tank.
- You can look at the spreadsheets I used for this data here
- Statistics were sourced from Basketball-Reference
- An Article by Jack Neubecker