Ever played poker with Bill Gates? Dan Harrington has.

“Action Dan” (poking fun at his tight play, like calling a bald man “Curly”) was a student at the prestigious Suffolk University in Boston when he took up poker, playing friendly games against Harvard University students such as Gates and Paul Allen, the co-founders of Microsoft.

Harrington also joined an MIT team that used mathematical formulae to gain an advantage at roulette – that is, until the Sands Hotel Casino in Atlantic City got wise.

Harrington, who also excelled at chess and backgammon as a student, brings the same calculating mind to the poker table. He has two World Series of Poker bracelets, winning the main event in 1995 and netting the $1-million top prize.

Harrington also finished strongly in 2003 (3rd place) and 2004 (4th). In all, “Action Dan” has nearly $3.6 million in tournament earnings.

How Harrington manages to finish so well without being aggressive baffles most observers. Because players know Harrington is tight, they will fold when he raises.

But Harrington, who keeps his job as a bankruptcy lawyer and also invests judiciously in real estate and the stock market, is all about minimizing risk. He bets strategically and satisfies himself with reaching the final table and the prize money that entails.

Harrington’s poker travels have taken him from New York (where he played at the Mayfair Club) to Los Angeles and then to Las Vegas, avoiding California’s state income tax.

Among his relatives are golfer Padraig Harrington and quarterback Joey Harrington of the Detroit Lions.