Every week, seemingly meaningless actions on the field of play affect gambling spreads. A late touchdown for a team that is getting blown out or a buzzer-beating 3-pointer for a team that already had a win in hand.
But rarely does a coach decide whether the bettors win or lose.
That's exactly what happened on Thursday night as San Francisco 49ers head coach Jim Harbaugh elected to decline a safety and instead take over on downs with 43 seconds to go, so as to not give the Seattle Seahawks a chance to get the ball back.
"I have never seen that," tweeted longtime Las Vegas bookmaker Jay Kornegay, who now runs the race and sports book at the Las Vegas Hotel and Casino. "Crazy to see that with the cover on the line."
By declining the safety, the 49ers ended up winning 13-6. Those extra two points left off the board hurt everyone betting on the 49ers to cover a 7- to 8-point spread. Those who took the Seahawks cheered in disbelief at Las Vegas sports books.
John Avello, head of the race and sports book for the Wynn in Las Vegas, said the reaction to Harbaugh taking points off the board was even crazier than it was in Week 3, when the replacement refs ruled that the Seahawks' Golden Tate scored a touchdown, giving Seattle the win against the Green Bay Packers, and all who bet on them the win against the spread.
The worldwide swing in bets for that game, including online and overseas sports books, was estimated at as little as $150 million and as much as $1 billion.
"This game was just as much of a swing, if not more," Avello said.
Although this was a Thursday night game compared to the Monday night game in Week 3, and Monday night games typically are bet on more, Avello said this game was particularly attractive to bettors.
All week, Avello said the 49ers were 7-point favorites. Then yesterday, the line at the Wynn moved by half-points all the way up to 9 before settling back down at 8.
"If Harbaugh took the safety, this would have been an absolute disaster for us," Avello said. "We would have had to return all bets at 9, which were almost all Seahawks bets, and everything else from 7 to 8½ were mostly 49ers bets, so they would have won."
USA Today betting analyst Danny Sheridan told ESPN.com that he estimates that $250 million to $300 million in total was bet worldwide on the game, with an average of 65 percent of the spread bets on the 49ers.
Gambling insider Jimmy Vaccaro, who has been in the industry for 37 years, said that he had never seen a coach take points off the board other than a roughing-the-kicker penalty on a made field goal. But he is well aware of the human element of the game and the gambling world.
"With the Packers game, it was in the hands of the replacement refs, and this time it was in the hands of Harbaugh's decision," said Vaccaro, who is now spokesman for William Hill North America, which sets the lines for 150 sports books in Nevada. "That's what makes sports betting so unique. There's always a human touch involved."
Vaccaro said he would bet "a billion dollars" that Harbaugh had no idea that his decision had any impact on gambling.
After the game, Harbaugh explained that simply kneeling on the ball would ensure that the game would be over, instead giving them to change to kick the ball after the safety.
"Otherwise, they'll onside kick it and you give them a chance to win the game," Harbaugh said.
Despite a down economy, Vaccaro said sports gambling results like this have remained very high-profile because the industry hasn't seen the dip that others have.
"No matter how bad the economy is, I've always said that two things stay steady: pizza sales and sports betting," Vaccaro said. "I don't know where they get the money from, but people have a hard time giving up that part of their life."