For the past year, Nevada casinos lived off gaming revenues produced by high-end baccarat players.
Baccarat gamblers played lucky during the month, causing Nevada gaming revenues to fall 4.7 percent, the state's third straight monthly decline.
Meanwhile, Strip casinos saw gaming revenues fall 6.4 percent.
According to figures released Wednesday by the Gaming Control Board, gaming revenues statewide were almost $847.2 million in May, compared with nearly $889.2 million casinos collected in May 2009.
On the Strip, casino revenues were $450.2 million in May, a decline of almost 6.4 percent compared with $480.8 million a year ago.
However, if results from baccarat are backed out of the equation, Nevada gaming revenues would have been off just 1 percent while the Strip would have reported a monthly increase of almost 1.4 percent.
"Baccarat has been a big positive for Nevada, but not in May," said Frank Streshley, the Gaming Control Board's chief of the tax and license division.
Gamblers on the Strip wagered $734.8 million on baccarat, an increase of 7.1 percent from a year ago. However, the hold percentage on the game went from a normal of 13.35 percent to 8.26 percent. The result being that casinos collected just $60.7 million, off by $35.87 million, or 37.1 percent, from a year ago.
The decline was the first loss Strip casinos suffered from baccarat in the past 13 months. The lower-than-usual baccarat numbers propelled the Strip to its largest monthly loss since last August. May also marked the Strip's second straight monthly decline.
"We estimate that had baccarat hold percentage been within the normal range, total Las Vegas Strip gaming revenues would have essentially been flat during May," Union Gaming Group principal Bill Lerner told his firm's clients in a research note.
High-end gamblers flocked to Strip casinos in May, lured by baccarat events surrounding Asian labor holidays. Meanwhile, the championship fight on May 1 at the MGM Grand between Floyd Mayweather Jr. and Shane Mosley attracted the high-end crowd.
Lerner said a Strip resort moved a large baccarat tournament from May to April, which may have skewed some of the results.
"In our view, results were modestly disappointing," JP Morgan gaming analyst Joe Greff told investors. "We note that results were impacted by tougher year-over-year comparisons particularly for baccarat."
During May, casinos statewide won $565 million from slot machines, which was down less than 1 percent from a year ago. Gamblers wagered $9.3 billion on slot machines, which was down 7.5 percent.
Nevada casinos won $269.9 million on table games, which was down 13.9 percent. Meanwhile, the money wagered on table game play was $2.5 billion, up 1.3 percent from a year ago.
For the first five months of the year, gaming revenues statewide are down less than 1 percent compared with the first five months of 2009. Strip casinos, which were helped by a nearly 32.9 percent increase in gaming revenues during February, have seen a 4.4 percent gaming win increase through May.
Casino revenues in Clark County fell 4.4 percent, but two reporting areas showed increases. Gaming revenues collected by casinos on the Boulder Strip were up 5 percent while North Las Vegas casino revenues rose 8.8 percent.
The locations were the only two reporting areas in the state that showed monthly increases. Many analysts believed the results were helped by the accounting method sometimes used in Nevada for counting slot revenues when two months share the same weekend, as what happened at the end of April and the beginning of May.
Greff said the increases on the Boulder Strip -- which includes Henderson -- and North Las Vegas, helped grow the locals gaming market by just less than 1 percent during May.
Downtown casinos saw revenues decline to $42.9 million from $43.2 million, a 0.7 percent drop and the smallest decline the market has seen since June 2008.
Streshley said the expansion at the Golden Nugget and other enhancements helped stabilize the market.
Contact reporter Howard Stutz at email@example.com or 702-477-3871.