John Riordan

John Riordan began his poker journey at the age of 13, playing play-money games online before transitioning to real money as soon as he turned 18. Due to Florida law allowing 18-year-olds to play in local card rooms, he was able to enter live tournaments in the state. His breakout came in 2011 when, at just 19 years old, he won the World Series of Poker Circuit (WSOPC) Main Event at the Palm Beach Kennel Club for $210,180. This victory made him the youngest winner of a WSOP Circuit Main Event at the time and marked his first recorded cash on The Hendon Mob. Under the online handle "mcallan25," Riordan spent years grinding the highest stakes of Pot-Limit Omaha (PLO) online, honing the skills that would later define his live career.

Riordan's early success was followed by two WSOP online bracelet victories in 2023, though specific event details remain sparse. His most significant achievement came in October 2025 at the Super High Roller Bowl $100,000 Pot-Limit Omaha event, held at the PokerGO Studio in Las Vegas. Competing against a field of 37 elite players, Riordan outlasted a final table that included Sam Soverel (runner-up, $825,000), Joao Simao (3rd, $550,000), Joni Jouhkimainen (4th, $400,000), Artur Martirosian (5th, $300,000), Bryce Yockey (6th, $225,000), and Jared Bleznick (7th, $150,000). Riordan entered Day 3 with a middling stack as Soverel dominated early eliminations, but he managed to double up twice during three-handed play and eventually took the chip lead heads-up. The tournament ended when Riordan flopped a nut flush draw and turned the flush, denying Soverel a full house. The $1,250,000 first prize was more than five times his previous best cash of $210,180.

Other notable results include a runner-up finish in a PGT PLO Series II $5,100 event in October 2025 for $103,700, as well as deep runs in the PGT PLO Series, Poker Masters, U.S. Poker Open, and ARIA High Roller events. Riordan has also cashed in multiple WSOP high rollers, including the $50,000 PLO High Roller and $25,000 PLO High Roller in 2025. His total live tournament earnings exceed $6.3 million placing him among the top PLO earners in the world.

Riordan's transition from online prodigy to live high-stakes specialist was seamless. He spent years playing the highest stakes of PLO online under the alias "mcallan25," which provided a rigorous training ground for the live super high roller circuit. Based in Palm Beach Gardens, Florida, Riordan is a regular on the PokerGO Tour (PGT), competing in events such as the PokerGO Cup, U.S. Poker Open, and PGT PLO Series. His online experience has given him a deep understanding of equities and variance, which he applies to the live felt.

Riordan is widely regarded as a Pot-Limit Omaha specialist, a game that demands both mathematical precision and psychological resilience. He is known for his unshakeable focus and calm demeanor, even in the most pressure-packed pots. His strategy relies on a combination of high-level mathematics and a strong "feel" for live play developed during years in the Florida cash game scene. Riordan employs a patient and disciplined approach, waiting for favorable spots to apply pressure. He is particularly effective in deep-stack situations, where he leverages positional awareness and pot control to maximize value and minimize risk. Opponents describe him as a quiet but formidable competitor who rarely makes mistakes.

Riordan's 2026 campaign has been strong, with a runner-up finish in a $10,500 high roller event for $60,000, as well as deep runs in the Wynn Millions and the PokerGO Cup. He continues to compete regularly in PGT events and WSOP high rollers, cementing his reputation as one of the premier PLO players in the world. From his teenage Circuit title to the pinnacle of the Super High Roller Bowl, Riordan's career trajectory exemplifies steady growth and adaptability. He has earned the respect of his peers and is often cited as an example of disciplined bankroll management and emotional control. His legacy is that of a player who combined online grinding with live excellence to become a champion on the biggest stage.