WASHINGTON &

The idea that a lone NBA referee could alter the outcome of games and go undetected for a long period of time is not a shocking one for handicappers who make a living establishing betting lines for NBA games.




Several sports handicappers interviewed Tuesday said that determining the betting lines on NBA regular season games is among the hardest tasks in the U.S. sports gambling industry, which takes in hundreds of billions of dollars in legal and illegal wagers annually. The difficulty arises because the teams play so many games and the effort of players tends to ebb and flow from night to night over the six-month regular season.




"I would be surprised if there haven't been refs fixing games for who knows how long," said Jimmy Boyd, who runs a sports gambling service based out of Las Vegas, where sports gambling is legal. "With the NBA, selectivity is the thing. The league keeps close wraps on the officials. I mean, they are under as much scrutiny as anyone, but if a guy were to space out a bunch of games over two seasons it's not going to be easily detectable."




Boyd's assessment highlights the challenge faced by the NBA and the FBI as they investigate former NBA referee Tim Donaghy, who is the subject of a federal inquiry into the possibility that he gambled on games he worked over the past two seasons and passed insider information to others who placed bets themselves.




NBA Commissioner David Stern said Tuesday that he believes Donaghy was a "rogue, isolated criminal" and that, to his knowledge, FBI investigators are not targeting any other NBA referees, players, coaches or league officials. Donaghy resigned on July 9, about 2 1/2 weeks after Stern said the FBI notified the league that Donaghy was part of a federal investigation into organized crime.




Donaghy, whose whereabouts are not known, is expected to turn himself in at U.S. District Court in Brooklyn, N.Y., sometime over the next several days. A voice mail message seeking comment from Donaghy's attorney, John Lauro, was not returned Tuesday evening.




Although Stern Tuesday did not identify any specific games refereed by Donaghy that have come under suspicion, sports gambling expert R.J. Bell said he has spotted some trends that suggest the possibility of tampering. Bell examined statistics on hundreds of games called by Donaghy over the last four seasons and published an analysis on his Web site, Pregame.com, which tracks sports gambling trends.




"This is a pattern you have to dig deep to see," Bell said. "The fact of the matter is, in hindsight, it's easier to see patterns because you know what you are looking for."




Bell said that while he found no obvious instances of outright tampering by Donaghy, certain trends emerged that raised questions in his mind. "What's so condemning in this case historically is that he was a passive referee," meaning he did not call an inordinately large number of fouls, "and then he became an active referee, and that's the sort of change you don't see," he said.




The NBA tracks the performance of its referees but does not make the statistics public. However, numerous Web sites run by fans and gambling aficionados keep their own records and analyze them.




Bell said that teams playing in games worked by Donaghy the last two seasons scored more total points than Las Vegas bookmakers expected 57 percent of the time. The odds of that happening naturally are 19-1, according to Bell.




Bell said high-scoring games usually are games in which a large number of fouls are called. A separate analysis by Covers.com, a Web site that tracks trends among NBA referees, showed that games played over the last two seasons games in which Donaghy worked had an average of 56.9 free throw attempts, tops among NBA officials.




Three referees work every NBA game, so it was impossible to say how many of those calls were made by Donaghy.




"The first thing I would look for is a guy calling a bunch of fouls on a key player early in a game or a bunch of ticky-tack calls at the end of a game," Las Vegas handicapper Tim Trushel said. "Fans are used to debating how a given game was called, so it's not like someone is automatically going to think it was fixed. If a guy is looking to hit the over" &

a bet that the total points scored by both teams would exceed the number established by bookmkers &

"one way to do that would be to call a bunch of fouls. Fouls lead to free throws and obviously, that leads to more points."




According to Bell, from Jan. 1, 2007, to the end of the regular season, the opening betting line &

the number that states which team is favored and by how many points &

of 12 games officiated by Donaghy changed — 1/2 or more points, which is an indication that a lot of money had been bet. In those 12 games in which the money was predominately on one side, the money was right in 10 of them.




"Guys betting big money were right 10 out of 12 times," Bell said. "To me, that's a key number. Going 10-2, the odds of that are only 2 percent randomly."




Trushel said rumors that an NBA referee had been "bought off" began to circulate among sports gambling circles in April. "That's when you started hearing things, that a ref was shaving points or fixing games, but at the time, you weren't hearing any names and it would be very hard to pick up on it if the guy was careful," Trushel said.




Trushel added that it is more difficult to detect a basketball referee who is seeking to influence the outcome of a game than it would be with officials in other sports.




"Basketball is different from the other sports," he said. "In baseball, the home plate umpire obviously has a huge impact on how balls and strikes are called based on their strike zone, but in basketball, you have three-man crews that rotate," meaning the same three referees do not always work together.




"So you'd have to look very closely to detect a pattern of a single guy altering the outcome of games," Trushel said. "The one question I have is: If he was doing this over a two-year period, how didn't any of the referees he worked with not detect something and say, 'What's going on?' "




Stern said Tuesday that the investigation is looking into whether Donaghy fed privileged information to associates who bet on games. One piece of information that could help a gambler is knowing which referees are scheduled to call a given game. The NBA does not release such schedules and encourages referees to tell only their immediate family members. Coaches and players don't learn which crew is working a given game until shortly before tip-off.




"If a bookie could get that kind of information, it could help," said one source, who declined to be identified by name because he runs an illegal sports gambling operation in the Washington area. "Obviously the ref could make more of a difference by calling the game himself, but there is a reason why the NBA doesn't list which refs are working which games ahead of time. If you're setting a line, any piece of extra information can help."