Blackjack is steadily losing ground in casinos as gamblers turn to "specialty" games that offer a shot at a big score but carry a higher house advantage.

Snow said about a quarter of the table games in North America are "proprietary" or "specialty," the preferred terms for what once were referred to as carnival games. Most are variations of poker and blackjack because gamblers are already familiar with the basics of those games.

Over the past 25 years, the growth of proprietary games has been steady, around a percentage point a year, he said.

Three Card Poker, which is marking its 20^th anniversary this year, is the current king of specialty games, but Snow predicted that Ultimate Texas Hold 'Em, one of his creations, will overtake it eventually.

Casinos pay as much as $2,000 per table per month to owners of specialty games. Blackjack side bets typically cost a casino $30 to $50 per month per table, with a few reaping $300 per month.

Snow said his first Las Vegas job was at the Mirage, where he saw the casino was paying Shuffle Master $2,000 a month for each of four Let It Ride tables.

The house advantage for specialty game varies widely. Free Bet Blackjack has a 0.6 percent house edge, while the Lucky Ladies side bet carries a house advantage of more than 20 percent. "There are more blackjack side bets than any other form of proprietary table game," Snow said. "There's a million different things you can do. You can come up with some sort of proposition. Instead of winning even money or 3-to-2, maybe I can win 20-to-1, 1,000-to-1."

Snow said casinos have seen their hold on blackjack decrease over the years as players have become smarter. In response, casinos adopted H17 and dropped late surrender. Pointing to Pennsylvania's player-friendly rules - including a statewide requirement that naturals pay 3-to-2, S17 and late surrender - he predicted that casinos will seek changes as players become more skilled. In mid-June, Maryland regulators approved H17 for blackjack games there.

The sweet spot for specialty games is guaranteeing the house a reasonable amount of profit but offering players a chance to win big. "These games are 50 percent math, 50 percent psychology," Snow said. "That ability to win money trumps everything else. That's why people go into a casino, to win money. I tend to create games with high volatility that allows a player to win a reasonable amount of money quickly. The corollary being that you can lose a lot of money quickly, too, but people tend to forget those experiences." "It's a very delicate balance, and in that balance are where success and failure are determined."

Snow has high hopes with "Go Fore It," a new Scientific Games offering developed by two employees of Meadows Casino south of Pittsburgh. It's different from other specialty games because it's based on golf, rather than blackjack or poker. Players get four cards, with a goal of having a lower total than the dealer.

"Themed table games are a thing of the future, and we'd like to be a pioneer of that," said co-developer Ben Kowalski, a lead casino shift manager at Meadows. "There's a void to be filled."

The game's Pennsylvania debut will be in July 2015 at Meadows. It's already being dealt at The Cannery in Las Vegas, owned by the same company that operates Meadows.