Michael Mahoney: The Online Chess Marathoner
Michael Mahoney, known on the board as sion2200, is a National Master with an appetite for online chess that borders on superhuman. Since 2011 he has built one of the most durable and high-volume profiles in blitz chess, playing tens of thousands of games while pushing his blitz rating to a peak of 2704 (2026-07-31). He is a creature of the fast lanes, with blitz as his home format and bullet not far behind.
Career Arc
Mahoney's rating graph reads like a mountain range drawn by someone with no fear of heights. After starting in the low 2000s, he climbed steadily through the 2010s, survived the occasional avalanche, and emerged in 2026 with the best form of his life. His ability to play more than a thousand games in a month while still improving is rare.
tells the story better than words.- Peak blitz rating: 2704 (2026-07-31)
- Longest winning streak: 22 straight wins
- Most loyal rival: grandemas with 453 games
Style and Openings
When Mahoney has the white pieces, he almost always reaches for 1.e4. The Caro-Kann Defense Exchange Variation and the Closed Sicilian Defense are his favorite battlegrounds as White, while as Black he is happy to steer into the Pterodactyl, the Classical Sicilian, or the Bogo-Indian. If there is a sharp or unusual line nearby, he tends to find it.
His numbers show a fighter who never stops. He reaches the endgame in 88% of his games, averages more than 80 moves in wins, and has a comeback rate of 86%. He also wins 62% of games against lower-rated opposition and remains dangerous after losing a piece, which explains his reputation as a nightmare to put away.
highlights the openings where he does his best work.Rivalries and Marathon Spirit
No biography of sion2200 would be complete without grandemas, his most frequent dance partner with 453 meetings and a nearly dead even score. Against A I, the story is tougher, with endgameattack holding a dominant edge. But Mahoney keeps coming back. His longest winning streak is 22 games, and even his longest losing streak could not keep him down for long.
Fast Chess Personality
Mahoney is at his best in the early afternoon, with his strongest winning hours around 14:00. His tilt factor of 15 suggests he feels the swings, but not enough to stop him. He has more than 29,000 blitz wins and over 10,000 bullet wins, with a preferred time control that leaves no doubt: blitz is his kingdom.