Lining Up Behind the 76ers

Going into the year, there was an honest discussion as to whether the 76ers would post the worst record in NBA history, topping their own record of 9-73 from 1972-73. (See here and here.) After 3 games…well, let’s just say that discussion’s been tabled. 3 wins in a month makes it hard to take a run at 8-74, especially when two of them are against the very best teams in the league. It’s going to take serious commitment to winning the Ender Game* for them to not scrape out another 6+ wins playing against the Raptors, Celtics, et al.

Still, I would say that the story is not that the Sixers aren’t historically terrible—it’s that they’re quite terrible and managed to beat three teams in four nights, two of which were expected to be very good.

Just how unexpected was this? There are obviously a few ways of looking at this. I could look to AccuScore, probably the most notable sports prediction engine out there, though I can’t find their early season NBA picks lying around anywhere. However, everything is more fun when there’s money involved, so we’re going to do this in terms of gambling. Specifically, if you bet the Sixers to beat the Heat straight up, then bet all your winnings on them against the Wizards, and did it again against the Bulls, how would you have done? Moreover, how often does a streak that’s this improbable occur?

Well, according to Odds Portal, if you’d started with $100 and kept reinvesting, you’d have a stake of $13,206.26, for a profit of $13,106.26. If you prefer a percentage return, since we picked $100 you can see this pretty easily—131x, or 13100%. This isn’t unheard of in sports gambling—someone made $375K on two $250 bets on the Cardinals in 2011—but it’s still quite impressive, especially given that these are single game bets rather than bets on a team winning the title.

How impressive is it? To answer that, I scraped NBA money line data from 2007-08 through 2011-12 from Sports Book Reviews, and while I can’t evaluate the exact accuracy of their lines, I figure it’s probably good enough. (They seem a little extreme, but I don’t bet enough basketball to say for sure.) I looked at every three game winning streak in that dataset, counting longer streaks multiple times, e.g. a five game winning streak is three overlapping three game streaks. (Playoffs and multiseason streaks are also included, though neither turned out to be relevant.) For each of those streaks, I calculated how much a prescient (read: lucky) fellow might have made betting $100 on the first game and entirely reinvesting.

(Quick sidenote: this is a fun exercise, but I’ll acknowledge it’s far from perfect. On a practical level, the data aren’t that trustworthy and the assumption that gambling lines proxy for probability estimates is shaky. More troublingly, on a theoretical level we would expect that the lines for the later games in a given streak shift some with a team’s wins in the first game(s). I don’t know enough to guess how much a given set of lines will jump around, but I suspect that this method overestimates the ex ante probability that a streak like this would occur. Also, if we guess that lines bounce around more in the early season, the odds on the Wizards and Bulls games probably dropped quite a bit, further underestimating how rare this streak is.)

Anyhow, as it turns out, only one team has had a three game streak that was as unlikely as these Sixers’ from a Vegas perspective. The post-lockout Wizards had a streak in April 2012 that is in some senses similar to the current Sixers’ streak. They were 14-46 and, with only six games to go, would presumably tank the shit out of the rest of the season for a shot at Anthony Davis. Instead, though, they beat the league-best Bulls on the road (at +675), Milwaukee at home (at +330), and followed it up by beating the eventual champion Heat in Miami (at +450). Riding them for those three games would have made you a profit of $18,228.75, which is just obscene—it’s an extra $5K (or 5000%) beyond the Sixers. As it turns out, they’d close out the season with three more wins, all as favorites, against two tanking teams and the Heat, who were presumably resting starters by then. If you’d kept piling on, those six games would have gotten you almost 47 grand…though it might have also merited an intervention.

There are only two other teams in the same ballpark as these Sixers and Wizards. The December 2007 Trailblazers picked up a profit of $10,956 and were buoyed by a win in Utah at +1200—apparently they had only won once previously on the road and were missing LaMarcus Aldridge. They were moderate underdogs the other two games (+170 and +215), but it was driven by that one game. The only other team above $10K (or even $8K) is the March 2012 Cavaliers at $10,508, who got there by winning at Denver and Oklahoma City.

So in nearly 5 years of data, we have one bigger streak and two that are in the neighborhood. As I said earlier, I think the Sixers’ streak is a little more unexpected than this method gives it credit for (even relative to other streaks), but by this method we figure that this is a once in five years occurrence, even if seems much odder than that right now.

All this said: even if I take the supposedly rational perspective that weird shit happens in small samples, it still doesn’t make me feel better about the Bulls’ blowing that lead last night, though. At least Rose is back: he’ll probably be fodder for posts later down the line.

*Andrew Wiggins is the presumptive #1 pick in the next draft. Andrew Wiggin is the real name of the protagonist of Ender’s Game. We can make this happen, people.

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