College Basketball’s Unmentionable: the Issue of Point Shaving?

Posted by rtmsf on September 13th, 2010

It’s not often that we stumble across academic research papers these days, but last week we happened upon one from the Department of Economics at Temple University in Philadelphia entitled, “Point Shaving in NCAA Basketball: Corrupt Behavior or Statistical Artifact?”  In the paper, Professors George Diemer and Mike Leeds use various statistical analyses to conclude that not only does point shaving regularly occur in college basketball, but it occurs in two specifically defined situations.  Their conclusion builds upon prior work by Professor Justin Wolfers at Penn’s Wharton School, who found a few years ago that approximately 1% of lined NCAA basketball games fell into an outlier suggestive of gambling-related corruption (the math works out to approximately thirty games per year).

This is the Only Shaving the NCAA Wants to See

Using data from a comprehensive sample of 35,000+ lined games from 1995-2009, Diemer and Leeds confirmed Wolfers’ underlying finding — statistical indicators suggest that point shaving in college basketball exists — while giving us a richer explanatory context of when it happens.  So when does it happen?  According to the authors, the data shows that the higher a point spread goes, there is greater statistical evidence of an increased incidence of point shaving.  In other words, there is a greater likelihood of favorites shaving off a few points when they’re favored by twenty points than there is when they’re favored by fifteen, ten or five points.  The intuitive logic behind this premise is that in games with large point spreads, the favorite (a far better team) can afford to give up a couple of meaningless buckets to its opponent at the end of the game because it will not impact the primary outcome — the favorite still gets the win, regardless of whether it wins by nineteen or fourteen points.  Conversely, in games with  increasingly smaller point spreads, players (or coaches, or referees) trying to shave points would have to walk a very fine line between trying to still win the game while simultaneously staying under the point spread threshold.  Given the thousands of confounding factors facing any one person trying to manipulate a final score in such a way at the close of a game, this scenario would seem much more difficult to pull off.

The second qualifier that Diemer and Leeds found was that the statistical tendency for the incidence of point shaving to increase along with the betting line only holds during regular season games; during the postseason (conference tournaments, the NIT, and the NCAA Tournament), there is no such effect.  The logical premise supporting this contention is similar to the above –  in postseason games, there is a much greater level of importance from all parties involved (not to mention public attention) to perform at peak capacity from start to finish throughout the game.  During the regular season, where presumably every team lives to play another day, this underlying motivator is less so.

Economists Are Better At This Than Us

You’re probably wondering how the authors can know something is fishy simply from looking at a bunch of excel spreadsheets of point spreads and game results over fifteen years.  After all, it’s not like they can show specific instances of point shaving by anyone in particular (such as Toledo’s Sammy Villegas), nor can they isolate which individual games were the most likely candidates of corruption.  They can only tell us that, given a normal expectation of how data aggregates in a gambling market, there are some trends that cannot simply be explained by random chance.  Similar to determining that numerous Chicago public school teachers were helping their students cheat on standardized exams or any number of other economic studies to explain human behavior at the macro level, the answer is that this is what economists do.

Obviously, just because it’s their job doesn’t make it sacrosanct.  Anticipating some criticism of the study, we asked Diemer and Leeds specifically about two possible issues with their findings.  First is whether the concept of line shading — when bookmakers move their betting lines one way or another to maximize their own profits — impacts their findings.  After all, if the assumption is that a gambling marketplace seeks to establish equal wagering from bettors on both sides of the point spread, then movement away from that magical 50/50 nexus could sway performance (i.e., the point spread doesn’t represent the true market odds).  The authors refute this by suggesting that if bookmakers were manipulating the line in such a manner, then the data would still represent as a symmetrical distribution — but it doesn’t.  No matter where the data falls on the curve, it shows the same result: as point spreads increase, there is a greater incidence of point shaving.

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All Ur Base R Belong 2 Us

Posted by rtmsf on October 28th, 2007

Remember this internet sensation from the early 2000s?

We couldn’t help but recall that fine piece of artistry when we came across a site called The Palace of Bling the other day. Turns out they’re going to be providing coverage of the college hoops season for the gamblers among us. Well, let there be no doubt where we plan on getting our hot plays from this year. We’ll save you the linkage by providing you with their full text so you too can see how impressive TPoB is when it comes to the point spreading department. Somehow, we’re not too worried about copyright issues. From our place turf, er, tribunal, to yours (best lines in bold):

Well the college basketball game season is almost upon us and our professional college hoops odds-makers are dusting off our tons of game-winning analysis and tendencies so that we can have got another winning season. For the last 10 years, we have got picked three college basketball game best stakes for pretty much each twenty-four hours of the regular season all the manner until the conference tournaments. With all of the tons of games across the nation, it is not reasonable to seek and disability each game because the whole point in this line of work is to go on to come up out on top in the point spreading department.

We look at every game each twenty-four hours but we settle down in on the three best dramas based on our historical information that have got been consistent victors for us each twelvemonth of our existence. We have got a accumulative record of picking at 59 % over those 10 old age and we look to go on to construct on that success for this season.

One winning tendency that we love to title-holder is our home underdog volts conference rival scenario. The manner we explicate such as a scenario is one where two squads from the same conference where the visiting squad is favored over the place squad. This is a very profitable winning tendency for many reasons. The greatest ground is the fact that schools happen it “insulting” tp be deemed unworthy of favourite position on their place turf. The fact that the incoming school is favored to travel in and beat out them on their place tribunal functions to add great motive to the insulted squad. We discovered this tendency back in our first twelvemonth of being and we have got used this as one of our tons of winning tendencies to continuously turn a profit. Over that ten-year era, these scenarios that we picked won at nearly a 64 percentage cartridge holder ATS. Now the cardinal to is to place which 1s are more than profitable than others because some schools don’t take to this tendency successfully. We have got a strong thought of who these schools are that win continuously in this scenario and that have helped us go on our winning ways. Just one of our many winning trends.

There are a short ton of great squads heading into this season and it will be interesting to see who will lift to the top in the epoch of hot shot prospects playing for one season before they travel on. We are on top of it all and expression to convey more than winning to our 100s of dedicated subscribers. It have been a long off season and college hoops are finally are almost upon us. Good fortune to everyone and let’s have got a great season. Also allow the winning begin.

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Tim Donaghy Scandal Fallout

Posted by rtmsf on July 21st, 2007

Much is going to be made over the next week over the disclosure broken Friday by the New York Post that Tim Donaghy, a veteran NBA referee, allegedly became heavily indebted through illegal gambling and was using his position as an official to manipulate point spreads by proxy of organized crime. In other words… pointshaving, quite possibly the dirtiest word in sports. The only good news for the NBA was that the news hit on a summer Friday afternoon after a week of wall-to-wall Michael Vick and Barry Bonds-related outrage coverage.

Tim Donaghy and Kobe

“Kobe, do you think you could help a fellow Philadelphian out here?”

The outcry already predictably ranges from the overtly dismissive from Nate Jones at AOL Fanhouse:

For some reason the ref story isn’t that big of a deal to me. Unless of course it comes out that the ref is 2006 Finals MVP Bennett Salvatore. I feel like there are bad apples in EVERY organization. So it’s not a surprise that one ref out of all of the refs in the history of basketball decided to go down the gambling route.

And Greg Anthony at espn.com:

While some who are critical of the NBA point to this being an organization’s problem, I see this more as probably one man’s human error.

To Bomani Jones of Page 2 accusing NBA brass of negligence for not sniffing this out sooner through its review process:

Should the reports be true, Donaghy worked for a league that couldn’t catch on to what he was doing. For all we know, the NBA couldn’t tell if Donaghy was blind as Jose Feliciano or as connected as Jack Molinas. In spite of having mountains of data on officiating, enough to produce a rebuttal to a scholarly paper about whether foul calls are affected by the race of the referee and the player whistled for the infraction, the NBA apparently couldn’t tell something was awry. That’s all bad for the NBA, and probably worse than it would be for any other league. After decades of cockamamie conspiracy theories and a season that will be remembered more for tanking than playing, the last thing the NBA needs is anything that could give credence to any allegations of shady business. Especially if the shade was brought on by negligence. Absolutely, corruption is worse than incompetence. But what’s worse than both of them? Hiring someone corrupt and not knowing any better.

To using this incident as a proactive agent of change, as Mark Cuban suggests in blog maverick:

Every company of any size has had a problem(s) that its CEO and stakeholders have lost sleep over. Its the law of big numbers. If enough things go on, something is going to go wrong. Products get recalled or are tampered with. There are workplace disasters. There is corruption. No industry is immune. Churches, consumer products, law enforcement, cars, planes, trains and plenty more. No profession is immune. From the CEO who misrepresents corporate numbers or events at the expense of shareholders, to the doorman who tips himself from the cover charge at the expense of the club owner, people of every profession make bad decisions. Shit happens. Bad Shit happens. When it does, there are two options. Cry over it and do nothing or recognize the problem and do the best you possibly can to not only fix it, but make the entire organization stronger.

To the downright apocalyptic from Jennifer Engel at the Ft. Worth Star-Telegram:

Whatever his previous failings, and his handling of that little Suns-Spurs brouhaha immediately jumps to mind, Stern obviously understands what is in danger of being lost. You. The fan. The guy who is left wondering what, if anything, you saw in the NBA was real. He understands this poses a far more insidious danger to his league than Vick does to the NFL or Bonds to Major League Baseball. They can make Vick go away. Bonds eventually will go away. Doubt is far tougher to suspend. Which is why the NBA has scoreboard on every other sport for the worst of the bad weeks.

To the Vegas reaction from NBA aficianado David Aldridge:

There was no detectable change in betting patterns in Las Vegas casinos on NBA games during the last couple of years, according to Jay Kornegay, who runs the sports book at the Las Vegas Hilton and spoke by telephone today. “We usually hear something if there’s some unusual movement or unusual betting patterns. . . . There’s usually some kind of discussions about them. We don’t remember anything like that,” Kornegay said. Kornegay said he wasn’t concerned about taking action on NBA games in the future. Sports book betting makes up only about 2 percent of all betting action, he said “We are a very well-regulated industry out here, and I have all the faith in the world in our system,” he said. “I’m more disappointed than concerned. It doesn’t just shake the NBA; it shakes the whole sports world.”

To the silly, from freedarko.com:

But in another way, this is really good for the league. Fine, some games–most likely regular season ones, which everyone agrees mean nothing–were competitively tainted. Yet this most ordinary of sports scandals might serve as a reality check on all the stupid shit people say about the NBA. This is how things are weird in a sport; the commish doesn’t write the script for the postseason in advance, the refs are programmed to give close calls to whoever garners the highest ratings, and China isn’t secretly controlling the whole thing from behind the muslin curtain.

To Marty Burns at cnnsi.com discussing the referees’ collective feelings:

We’re angry. We’re angry. That’s for sure,” he said. “It’s not fair that one guy, one bad apple, brings down the whole officiating [staff]. It’ll trickle down to the college game, too. Every controversial call at the end of a game, somebody will question it… “I am sick of having to defend ourselves. We just got over the IRS thing, and now we have to defend ourselves all over again.”

To the deserving self-aggrandizement of Unsilent at Deadspin for “calling it” (did he have money on which ref it was?):

Just as I predicted Donaghy was identified as the target of the FBI’s gambling investigation. [...] Of all the refs I heckled last year there were only two that could really piss me off. One was a dick (Steve Javie) and the other was either the most incompetent referee alive or a soulless shell of humanity with mob ties. I have no idea whether he had money riding on any of the seven Wizards games I watched him work this season, but it sure would clear things up a bit.

To Jack McCallum at cnnsi.com quoting pejorative attacks on the man’s character:

The league source close to Philly put it this way: “He’s the kind of guy who is always in fights. When he was a kid, you’d see him throwing rocks at cars. He’s just an asshole. No one likes the guy. He’s always in fights on the golf course, that kind of thing. He’s a very antagonistic guy. When you have too many enemies, one of them comes back to bite you.”

In other words, a little bit of everything. Already we’re seeing evidence of every local NBA paper taking a closer look at games in which Donaghy worked. Feel free to interpret “worked” in any way you choose there. We’ll be back tomorrow with a closer look at how we feel sports gambling potentially impacts sports at both the collegiate and professional levels. Our essential conclusion is that this sort of thing happens a lot more than we all think. Unfortunately.

Update:  Simmons puts his ten cents worth here while Henry Abbott at TrueHoop and Dan Shanoff call for transparency.

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