Daniel Harrington

Daniel Harrington is an American professional poker player who rose to fame by winning the WSOP Main Event. He has authored several poker strategy books (such as the Harrington on Hold’em series), widely regarded as essential reading for Texas Hold’em and influencing countless players.

Harrington won the WSOP Main Event and has made multiple WSOP final tables. He has also performed well in other major tournaments and is recognized as one of the top players in the poker world. Beyond his tournament results, his poker books have made significant contributions to strategic theory, with translations in multiple languages.

Harrington’s style is based on tight-aggressive (TAG) play, emphasizing mathematical calculations and probability analysis. He excels at making precise decisions based on opponent ranges and pays close attention to chip stack management. Despite the nickname “Action Dan,” his actual game style leans more toward solid, systematic thinking.

The nickname “Action Dan” originated from his early online screen name, but his tournament style does not match the usual meaning of “action.” Harrington has appeared on poker TV shows such as Poker After Dark, showcasing his calm table demeanor. His book covers often feature him wearing sunglasses and a baseball cap, which has become an iconic visual symbol.

Harrington’s books emphasize fundamentals and logic, making them suitable for players from beginners to intermediate levels. The concepts he popularized, such as the “M-ratio” (M值) and “Q-ratio” (though not originally his inventions), help players understand urgency in tournaments. Readers can learn how to think structurally, manage their bankroll, and avoid emotional decisions.