Serafym Oliinyk: A FIDE Master Built for Blitz
Serafym Oliinyk, known to opponents as Sem1901, is a FIDE Master who treats fast chess the way sailors treat weather: constantly, obsessively, and usually from the helm. His preferred battlefield is blitz, where since September 2024 he has played hundreds of games, ripped off a 13-game winning streak, and pushed his peak blitz rating to 2692 (2026-03-16). The chart below tells the story in one glance: a modest starting point that turned into a rocket.
The d4 Laboratory: London System and Friends
Open with 1.d4 against him at your own risk. Serafym began games with d4 nearly 200 times in 2024 alone, and his signature weapon is the London System, specifically its Poisoned Pawn Variation, an opening that sounds dangerous because it is. By 2026 he had drifted toward Nf3 move orders, transposing into the same beloved structures while keeping opponents guessing.
With Black he rotates through the Grünfeld Defense, the Modern, and the Sicilian Defense, and when he reaches the Najdorf Main Line he wins nearly 78% of the time. Somewhere in the repertoire there is also the Colle System's Rhamphorhynchus Variation, a line apparently named after a pterodactyl, which is exactly the correct energy for something this sneaky. In bullet, the Amar Gambit and the Australian Defense come out to play, because when the clock runs on 60 seconds, paleontology and geography are both fair game.
A taste of the Poisoned Pawn: two queens staring each other down while the c-pawn stares at your patience.
Nemesis Files and the Undefeated List
Every grinder has a villain. For Serafym it is Mikhail Fayuler, met a dozen times with a ledger that stubbornly refuses to tip his way: 4 wins, 7 losses, and one diplomatic draw. Against Volodymyr Molyboha the story flips to a crisp 5-1, and the rest of the dossier reads like a highlight reel: 4-0 against iloveguppy, 3-0 against both ramla2020 and omartoom. Somewhere out there, mishan83 is smiling. Statistically, that smile is probably warranted.
Style: Endgame Steel and an 88% Comeback Rate
Serafym's games reach the endgame 86% of the time, which tells you his middlegames end in results, not miracles. His average win runs about 80 moves; his average loss runs 92, meaning when things go wrong he does not go quietly. He still wins over half his games after dropping material, and only about 2% of his losses are truly one-sided.
- Comeback rate near 88%: lost-looking positions get rescued with suspicious regularity.
- Over 700 rook checks in 660 analyzed games, and exactly two checks ever delivered by his king. The king stays home. The king has chores.
- Nine career checkmates across all analyzed games; most opponents resign first, which he considers a compliment.
- He resigns like a gentleman: when the position says it's over, he agrees with the position.
Clock Edge: Wednesdays, Noon, and the 3 AM Experiments
The calendar is a weapon. Serafym wins about 69% of his games on Wednesdays and nearly 68% on Fridays, while Sundays sink to a charitable 42%. Noon is his golden hour at a 74% win rate, and his three recorded 3 AM blitz games all ended in wins, which raises questions about sleep that science is not prepared to answer. Rated games bring out his best by a wide margin over casual ones, a man who saves the serious stuff for games that count.
As for rapid chess, the record stands at 0 wins and 2 losses, so if you ever spot Sem1901 in a rapid lobby, assume someone hid his blitz app. Everyone else: challenge him at your convenience, but maybe not on a Wednesday at noon.