In January, Daniel Dobson was two months into a new job that allowed him the opportunity to travel overseas and watch live sports. It had a downside, though: It got him arrested in an incident that drew media coverage around the world.

Dobson’s job was to sit courtside at the Australian Open in Melbourne and use his cellphone to transmit the outcome of each point of the match he was watching. The faster he worked, the greater the edge his employers at Sporting Data Ltd. would have in the betting market.

Police charged Dobson, 22, with violating a law protecting integrity in sport. Two months later, they dropped the charges, and today Dobson works out of Sporting Data’s London office. The experience convinced Sporting Data chief executive and co-founder Steve High to drop tennis courtsiding from his firm’s portfolio.

“That’s it for us,” he said in an interview at the company’s headquarters last month. “We’re not going to do that anymore.”

Now that he doesn’t need to protect his company’s tennis tactics, or stay mum during a high-profile investigation, High is speaking freely about courtsiding. His colleague Richard Coughlan is also talking, and a former courtsider for another company has written a book on the topic to be published this week. All three describe careers that parallel those of the players. Courtsiders travel the world alongside the tennis tours, spend hours of each day honing their craft, seek to make it to the highest-profile matches to earn a big payday and, if they’re booted early in the week by their opponents, kick back and enjoy touring glamorous cities.

“Oh, I loved it,” Coughlan, 27, said of his courtsiding job, which paid an annual salary of about 40,000 pounds ($67,000). “I’d love to still be doing it now.”

Officials crack down

The vigorous opposition of tennis officials to courtsiding has made it impossible to continue. Coughlan and Brad Hutchins, author of the forthcoming “Game, Set, Ca$h!,” say tournament directors use a network of scouts, security officials and sometimes police to sniff out people transmitting scores. The sleuths are aided at times by disapproving chair umpires, photographs of known courtsiders and, according to Hutchins, closed-circuit television.

Tennis has an uneasy relationship with gambling. In 2007, the sport was roiled by a high-profile incident of irregular betting involving top-10 player Nikolay Davydenko. (Davydenko insisted he was innocent and no evidence was found implicating him.) Partly in response, in 2008 the international organizations that oversee the professional game jointly formed the Tennis Integrity Unit. The TIU standardized rules on betting, including banning spectators from transmitting live scores for commercial purposes. (The secretive, London-based group doesn’t disclose its budget or staff size, and its spokesman told me its policy is not to comment except about cases it has already made public.)

Yet the sport also seeks to share in the revenue from the popularity of tennis gambling. The website Bet-at-home.com is a sponsor and the namesake of men’s tournaments in Hamburg, Germany, and Kitzbühel, Austria. And the top customers for the sport’s scores are gambling websites.

Tennis bans courtsiders to protect the sport’s integrity, U.S. Open tournament director David Brewer said. That courtsiders might be involved in more problematic betting-related behavior like match-fixing “would certainly seem to be a logical conclusion that some people could reach,” Brewer said, adding, “Where there’s smoke, there’s fire.”

Scott Ferguson, a betting-industry consultant, rejects this logic. “There is no connection whatsoever between courtsiding and match-fixing,” he said in an email. “Hell, if you were fixing a match, why on earth would you need to be in the crowd? You’d get as far away as possible to avoid detection.”

High and Hutchins said they think tennis authorities are cracking down to protect the value of their own scores product. In 2011, the men’s and women’s tours made a deal to sell their scores through a company called Enetpulse, majority owned by IMG. Many of the buyers are sports-gambling websites that provide the scores for in-play betting — wagering on the match after play has begun. One site that reportedly buys the scores, Betfair, is a betting exchange that, like a stock exchange, pairs buyers and sellers for transactions when they are willing to agree to the same terms.

A spokesman for IMG said the company believes the tennis tours “should be the providers of the official data, thereby benefiting the sport and allowing funds to flow back into the game.” Spokesmen for the ATP and WTA, the men’s and women’s professional tennis tours, said the tours jointly invested more than $10 million to create and operate their system for collecting and distributing live match data. A spokeswoman for the Fédération Française de Tennis, which runs the French Open, said the FFT bans courtsiding because it “owns the right to the data.”

High said the tours could drive courtsiders out of business by providing a product as fast as their competition’s — or faster, if they took advantage of proprietary high-speed wireless networks at tournaments.

Time is money

Both sides in the cat-and-mouse game owe their jobs to the nature of tennis scoring data. After each point ends, chair umpires enter the outcome into computers, which transmit the scores to fans and bettors around the world.

The snag for bettors is that chair umpires aren’t primarily concerned with entering data instantaneously. They follow the ball along with line judges and watch the players to make sure neither one challenges a call, and on clay courts they often spring out of their chairs to check ball marks and ensure calls are correct. There can also be an electronic delay in the data they transmit.

The potential for delays means someone who can get score data faster has an advantage. That’s why courtsiders are courtside. The second the ball lands out, or bounces twice, they can click a button on their phones and transmit the score directly into the servers their employers use to place bets. The servers, in turn, contain software that models the outcome of the match. The model incorporates the latest point outcome, spits out a probability of each player winning, and then places any bets it can find that it considers favorable based on its calculated probability.

That’s basic courtsiding. A more advanced courtsider will get to know the players and their tendencies, and sometimes make calculated risks to gain a bigger betting edge. Suppose a player on the run throws up a lob. If his opponent’s body language suggests it’s going out, the courtsider can record the point as over before it’s officially ended. Or he might call a shot out before the line judge does, trusting his own eyesight and judgment.

Such advanced maneuvers should be used carefully — a premature decision could be costly.

“We’d rather be sure,” High said. “If it’s an absolutely critical point, you don’t want to be wrong.”

His courtsiders typically got local phones, testing different providers for the best coverage and speed. They rigged the phones with buttons that were easier to press without looking, by reaching into their pockets or even pressing them from outside their pockets.

Courtsiders tried to get to tournaments early in the day, to get seats behind one of the players for optimal viewing. They regulated their liquid intake to avoid poorly timed toilet breaks. “You hold, hold as long as you possibly can,” Coughlan said.

Coughlan was an active courtsider for 18 months, through last summer’s U.S. Open. At the peak of Sporting Data’s operation, each of its courtsiders was relaying data 30 to 35 weeks a year, three days a week, three or four matches a day. Tennis is ideal for live scoring because tournaments typically stage many matches simultaneously. If one is lopsided and driving no betting, courtsiders can shift to a different match.

After getting used to the job of keeping score, “you almost zone out,” Coughlan said. Then at crucial moments in the match, “you really have to really switch on.”

I asked him to show me how he’d record the score. He said I wouldn’t see, and I didn’t; he was that good. He could applaud a well-played winner while deftly tapping the right button on the phone in his pocket. He’d usually pick a player to support, going with the crowd whenever possible so as not to stick out.

Before prospective courtsiders were sent out to work, they were tested in the office, racing to see who could record points fastest. And they were told not to drink during tournaments after company tests — conducted by assigning employees the onerous homework of drinking heavily — showed hangovers weren’t conductive to fast, accurate match-scoring.

Most of the courtsiders were young men. High, who turned 49 in January, worked mostly out of headquarters in London. “I’m an old man,” he said. “It’s a young man’s game.”

It’s also a career with a limited lifespan. When tournaments catch a courtsider in the act, they typically boot the offender and ban him from returning, on threat of prosecution. Hutchins describes in his book a folder with headshots of known courtsiders that he kept seeing at tournaments. When he repeatedly was booted early in tournaments, he knew his days on tour were numbered.

“One of our guys got on first-name terms with security,” High said. “At that point, he knew his career was drawing to a close.”

‘We broke a million’

Sporting Data occupies office space in a storage facility in southwest London, not far from Wimbledon, the International Tennis Federation headquarters and the National Tennis Centre, but not as posh. Inside are a few desks and lots of computer monitors and screens, plus a conference room that doubles as storage space.

Sporting Data placed tennis bets primarily on Betfair, which imposes a five-second delay on bets. Often, Sporting Data would get score information from its courtsiders more than five seconds before the official scoreboard updated. Between its data speed advantage and its predictive model — which incorporates each player’s probability of winning serve and return points — it could find advantageous bets.

Some of the people on the other side of Sporting Data’s bets probably were casual gamblers who based their wagers on the match broadcast or the digital scoreboard. Others might have been betting with their hearts, when a favorite player was in a tough scrape. Some might even have been rivals whose own courtsiders were sending in scores even faster, or who used models that disagreed with Sporting Data’s.

The identity of the person on the other side of his bets didn’t matter, High said. “The clearest point I want to make is, he’s a guy who wants his bet to be matched.”

Naturally, Sporting Data lost a lot of bets, because knowing about just one more point than your betting counterpart often provides only a minuscule edge. But it won enough bets to make the whole enterprise worthwhile. “We broke a million” pounds ($1.7 million) last year, High said, though that was before expenses on courtsiders and Betfair charges. “From a purely business point of view, I would say the margins were good but not extraordinary,” he said.

The business didn’t depend on fixing matches or seeking inside information at tournaments, High said. He said his employees never corrupted the sport, and bristled when some of the press coverage of the Daniel Dobson arrest referred to an alleged “betting scam.”

High got into tennis betting after working for Reuters and then Betfair. He and several partners formed a syndicate to pool their bets and agreed to split winnings. Sporting Data is the company they created to provide the syndicate with data.

At first they were getting their scores from the official scoreboard, and betting without a model. Then they found a model online and adapted it for their purposes.

High speaks with some pride about his firm’s increasing competitiveness in tennis betting, much like a coach might speak proudly of his protégé’s career progression. “We went from being fairly slow, and not having a model, to operating on a Wimbledon final,” he said. At its peak, tennis was producing about half the syndicate’s profits, with horse racing generating much of the rest.

Coming into conflict with tennis authorities, and occasionally getting booted, was a cost of doing business. But an arrest wasn’t part of the plan. “We were aware that the authorities didn’t really like it, but there was no suggestion it was illegal in any way,” High said.

High described the aftermath of Dobson’s arrest as stressful — for his young employee, for Dobson’s parents, and for High and his colleagues, who stayed in touch with Australia in the middle of the London night. After the arrest, Sporting Data launched a website whose sole content was a statement asserting that “it has never been and never will be involved in any illegal betting or any other illegal activity whatsoever,” and that Dobson couldn’t be guilty of the 2013 law under which he was arrested because recording scores doesn’t affect match outcomes.

The company endured about a week of intense and often negative media coverage. “Once people understood we weren’t some sort of criminal organization cheating people out of money, the whole thing died down pretty quickly,” High said.

A spokeswoman for Tennis Australia, which runs the Australian Open and which reportedly flagged Dobson to the state of Victoria police, said she would send answers to written questions but didn’t. After the charges against Dobson were dropped, the police issued a statement saying the decision “should not be seen as an invitation for people to attend the Australian Open next year and engage in courtsiding.”

High thinks other companies, including Hutchins’s, also pulled out of courtsiding after the arrest. Coughlan can tell some courtsiders are still active simply by watching the in-play betting markets for matches on Betfair. When the odds move before the score has changed, he knows one of his former peers is at the match.

Now that Sporting Data has exited tennis, it’s had to lay off some employees. It’s focusing on soccer and horse racing.

High is considering ways to re-enter tennis based on intelligence advantage, not a speed edge. For instance, do Asian bettors drive up the price of Asian players beyond what they merit? Betting psychology may be the next frontier, High said. “I think that’s underestimated.”