A 13-minute error and the erosion of the bettor-bookie relationship

On a Tuesday afternoon in October, three hours before the NBA season tipped off, word began to spread in the online betting community. There was an error in DraftKings’ odds on the Los Angeles Lakers–Denver Nuggets game.

The over/under lines on players’ points, rebounds, assists and other statistics were wrong. Nikola Jokic‘s points were being offered at 9.5 when Jokic averaged 25.7 points per game the previous season. The over/under on LeBron James‘ points was set at 8.5, but James has averaged 27.2 points per game for his career.

Matt McAfee, a 36-year-old sports bettor in Indianapolis, caught wind of the mistake at approximately 4:25 p.m. ET. A handicapper and content producer for “GoldBoys,” a Discord popular with bettors, McAfee comes across errors on sportsbook apps frequently. This one on DraftKings, though, was more egregious than normal.

McAfee knew he would need to act quickly but first had to decide if it was even worth it. His betting limits on DraftKings had been slashed significantly after he capitalized on a controversy involving Draymond Green in January 2022.

“Since then, I haven’t been able to put more than about $10 on a same-game parlay,” McAfee told ESPN.

McAfee considered holding off but ultimately decided to see how much he could wager. To his surprise, he was able to place a $100 seven-leg parlay with 150-1 odds.

With bets like over 5.5 points for Nuggets forward Michael Porter Jr., who has averaged 17.5 points per game and over 8.5 points for James, each leg of his parlay had hit by early in the third quarter. He had won $150,000 but wondered if he’d get paid.

McAfee’s bet was among the hundreds of parlays that were placed on the bad lines in states around the nation. What happened next — in just 13 minutes — is the latest example of how hostile the bettor-bookie relationship has become in the modern American betting market.

In 2023, approximately 93.8% of money bet with U.S. sportsbooks was placed online, according to gambling research firm Eilers & Krejcik Gaming. In the past, bettors would have regular personal interactions with their bookmakers, either at the sportsbook or over the phone.

Today, though, very few of the new generation of sports bettors will ever meet the face behind the screen accepting their bets.

“The younger mentality of all these 21-year-old kids, they don’t have this respect of the industry,” McAfee said. “There’s never going to be a relationship like that. The big companies aren’t interested in building a relationship like that.”

What happened on the opening night of the NBA season is a prime example of why.

Sportsbooks have rules regarding obvious errors and most, but not all, states allow companies to void bets placed on the mistakes. DraftKings defines an obvious error as “odds that are materially different from those available in the general market at the time the bet was placed.”

According to DraftKings, a mistake by a third-party odds-provider caused the over/unders for just the first quarter to be uploaded into the betting market for the full Lakers-Nuggets game. The over/under on James’ points against the Nuggets was set at 23.5 at other sportsbooks, materially different from the 8.5 at DraftKings.

The bad lines at DraftKings were up from approximately 4:22 p.m. to 4:35 p.m.:

• In Massachusetts, 178 bets by 138 individual customers were placed on the bad lines, according to a filing by DraftKings. The total amount bet on the parlays was $4,182, with the largest wager $500; the total potential win was $575,436.82.

• The New Jersey Division of Gaming Enforcement said 215 winning wagers were placed on the bad lines with DraftKings but did not reveal the total stakes or payouts.

• The Connecticut Division of Consumer Protections, which oversees gambling in the state, said DraftKings asked to void approximately 80 bets with a total payout of $151,000.

In 18 states, including Indiana, where McAfee resides, DraftKings was permitted to void all bets on the erroneous odds. New Jersey and Connecticut were the only jurisdictions that forced the sportsbook to pay up. DraftKings declined to reveal the amount of total winnings it voided, but extrapolating from the figures that were disclosed in Connecticut and Massachusetts, it was easily in the millions of dollars.

At 7:59 p.m. ET, roughly 25 minutes after the Lakers-Nuggets game tipped off, McAfee received an email from DraftKings, notifying him that there was an issue with the odds included in his parlay and referencing the sportsbook’s house rules. McAfee questioned why the sportsbook had waited until after the game had started before making the decision.

“In my core, I believe if it would’ve benefited them, they would’ve scooped it all,” McAfee said. “It was a free roll for them.”

McAfee said he contacted the Indiana Gaming Commission about the issue but received no help. He says he has also contacted an attorney who specializes in consumer affairs to see if he has any recourse. Two months after the game, though, McAfee remains frustrated and without his winnings.

“In general, DraftKings and sportsbooks have carte blanche; they determine when and if they can void a bet based on their terms,” McAfee said.

Mistakes happen

This isn’t an issue exclusive to DraftKings. Errors by bookmakers have always been part of the sports betting game.

At sportsbooks from Las Vegas to London, big favorites have accidentally been listed as underdogs, and the occasional typo has turned 6-1 odds into 60-1. Like any large, dynamic data-entry project, mistakes happen. For example, in 2019 a glitch in FanDuel’s in-game odds caused the Denver Broncos to go from a commanding -600 favorite over the then-Oakland Raiders to a 750-1 long shot late in the fourth quarter, despite moving into position for a winning chip-shot field goal.

Bettors are typically the first to spot and capitalize on the errors. In the days when you had to walk up to the counter to place your bets, making a big score on a bad line was difficult, but bookmakers still didn’t like it. If a bettor took advantage of a mistake in the past, bookmakers often issued an ultimatum to resolve the issue privately: Agree to void the bet on the bad line and continue to be allowed to wager, or get paid out on the bet and be banned from playing at the sportsbook ever again.

These days, modern technology has made such errors far more lucrative for bettors and far more dangerous for sportsbooks, the largest of which are offering upward of 100,000 different betting markets daily. A bookmaker may make only one mistake in a week, but it will be caught and exploited in minutes.

Bettors have formed online communities to share tips about bad lines or point out when a sportsbook fails to take down a betting market on an event that has already been completed. McAfee says this past baseball season odds on a player to hit a home run were left up after the player already hit a home run, and bettors pounced.

“When something goes wrong, people will find it,” McAfee said. “There’s such a crazy strength in numbers where people are scouring these things constantly. I just love that it’s kind of a us against them mentality, where let’s try to get as many people to hit them as possible.”

On Nov. 30, McAfee and some fellow bettors tuned in to a five-hour Massachusetts Gaming Commission meeting that was broadcast on YouTube.

Item 7b on the agenda was DraftKings’ request to void the bets made on the bad player prop odds on the Lakers-Nuggets game from a month earlier. Jacob List, senior director of regulatory operations for DraftKings, reasoned with the commissioners, stating that errors in odds may occur in only “0.01%” of the 100,000 betting markets the sportsbook offers daily. List said that rules are in place to protect the sportsbooks because the tiniest typo can lead to a massive loss.

“So whether it ends up being $150 or $150 billion may not be really related to the size of the control failure at all,” List said. “And that’s why we have these house rules for these types of exceptions.”

Members of the five-person commission were conflicted on how to rule. Commissioner Eileen O’Brien noted that what the bettors did was not illegal and expressed concern that Massachusetts residents weren’t being treated fairly. Commissioner Jordan Maynard told List that he wasn’t convinced that “if by some miracle LeBron James stayed under eight points that game, that you would’ve come in and asked to void this” but also believed the bettors were exploiting the mistake.

“The thing that is pulling me is it’s in the best interest of the Commonwealth not to have … trolls … basically take advantage of your company,” Maynard said.

McAfee was offended by being referred to as a “troll” but acknowledges the ambiguity of taking advantage of obvious errors.

“I think it’s in a gray area. It’s not illegal, but would I like it if it happened to me? No,” he said. “The other side of the argument is that I also have the built-in understanding of how predatory the business model is and how exploitative they can be.

“For them to claim moral superiority,” he added, “I think that’s the part that pisses me off. We’re the undesirables, we’re the trolls? They would’ve kept the money if LeBron got hurt.”

A DraftKings spokesperson told ESPN that when an error in the odds is identified that it attempts to notify customers that there is an issue as soon as possible and that all bets made on the bad lines — winning or losing — are voided and the stakes returned to the customer.

The Massachusetts Gaming Commission ultimately ruled in favor of allowing DraftKings to void the wagers with a stipulation that each of the 138 patrons who had bet on the bad lines were given three times their initial stakes.

“That’s an easy cancel to me,” said Adam Bjorn, who, as a longtime professional bettor turned bookmaker, has been on both sides of palpable errors, as they’re known in international betting markets.

Bjorn says he specialized on pinpointing and capitalizing on palpable errors during his betting days, but after having so many sportsbook accounts closed, he learned that maintaining good relationships with bookmakers was more valuable.

“I’ve been on the other side for almost 30 years as well,” Bjorn, who now manages the odds and risk for new Ohio sportsbook, Prime sports, said, “There’s a lot of customers that get a lot of favors from me, because they alert me of palpable errors. So their accounts very rarely get restricted.”

Bjorn says uniform rules are needed to address bad lines and believes regulators too often side with the sportsbooks in such cases, but with the patchwork of state laws overseeing the fledgling U.S. betting market, it’s unlikely there will be uniformity any time soon.

In the meantime, the battle between bookmakers and bettors remains as fierce as ever. As long as bettors feel they’re being treated unfairly by sportsbooks that routinely cut sharp customers off, they’ll continue to exploit errors, and bookmakers will look for ways to combat them and protect their bottom line. It’s destined to be a never-ending fight for the other’s money, with neither side willing to say they have enough.

“Realistically,” List said, “even though we are constantly improving our controls, constantly improving our monitoring, constantly improving the ways in which we detect the type of customers that would abuse errors, there’s going to be more errors in the future and one of them might financially cripple our company.”

Asked about List’s claim of the company potentially being crippled by an error, McAfee said, “No it wouldn’t. We know how much they’re making.”