A competitor of lesser ability, on a lucky day, can beat even the best in the business. It happened on June 6, 1919, when Man O' War, perhaps the greatest racehorse of all time, lost the only race in his 21 starts. The horse that beat him was a 100-1 shot, and while his name might not be the reason the word appears above some of the biggest stories of all in sports and politics, it was, for the record, Upset.

Luck plays a role in every endeavor. But when it plays a big role, it's called gambling, which in New Hampshire and many other states is illegal. The law treats games of skill and games of chance differently, but it's not always easy to tell which is which.

Chess, for example, is considered to be a logical game of skill, poker a game of chance, or at least some mix of skill and luck. But the best chess player in the world could lose to a lesser player if, let's say, gout attacked his big toe during the match. Luck, that day, would have been with the victor.

Last fall, Congress banned the use of credit cards for online gambling. The law, designed to address increasing reports of gambling addicts losing it all in games played over the internet, exempted horse racing and trading in the stock market. Poker players want a similar exemption, and we say, deal them in. Sure, there's luck involved in poker, but it's a game of skill.

Billions of dollars are riding on one bill that would grant poker an exemption and regulate it and another that simply defines poker as a game of skill.

The issue could be settled in academia. Several universities are studying the mathematics of the one-time saloon game and creating computer programs that could do for poker what IBM's Big Blue did for chess.

A daylong meeting of professors and poker players was recently held at Harvard to discuss the luck-versus-skill issue.

The most convincing testimony, as reported last week by The Wall Street Journal, came from two siblings who grew up in Concord, Howard Lederer and Annie Duke. Lederer is a four-time world poker champion, and Duke is the all-time female leading money winner.

Poker, we're willing to bet, will be proven to be a game of skill. In fact, mathematicians are close to being able to predict the move with the best odds of winning any given head-to-head contest between two Texas hold 'em players. Duke cites simpler evidence. Poker has to be a game of skill, she told the Journal, because unlike the lottery you can lose on purpose if you want to.

Her brother played a different card. The "vast majority of high-betting poker hands are decided after all players except the winner have folded," he said. So if you can win most of the time without even showing your cards, it isn't because you're lucky.

Chance will still come into play in the short run. As Lederer argues, making the perfect mathematically justified play every time works only against another great player in a pure situation. The best player in the world could still be beaten by a fish who makes a bone-headed move. But in the long run, skill prevails and fish lose.

Congress should grant poker its rightful status as a game of skill.