Kim Sergey (sergeikim): FIDE Master and Marathon Man of Online Blitz Chess
Kim Sergey, known on the leaderboard as sergeikim and on paper sometimes as Sergey Kim (a name that refuses to commit to an order), is a FIDE Master whose real monument is not a trophy cabinet but a database: nearly 47,000 rated blitz games, a climb from 1593 to a 2772 peak, and a lifelong, unwavering devotion to the move 1.d4.
The Marathon Man of Online Blitz Chess
Some players build a reputation on a handful of immortal games. Kim Sergey built one on arithmetic: 21,048 blitz wins, 21,792 losses and 4,129 draws since 2017, a career record so close to an even 50% that the symmetry starts to look intentional. Volume is the strategy, and the strategy has been executed with religious consistency for nearly a decade.
But the numbers hide the real story, which is stubbornness. Nearly 86% of Sergey's games reach an endgame. Losses average 83 moves while wins average 75, meaning even when things go wrong, the opponent still has to finish the paperwork. Fewer than 1% of lost games are one-sided, and when an opponent lands an early check (a situation that drags the win rate down to 37%), Sergey usually punches back anyway. A comeback rate near 90% is not luck; it is a lifestyle.
The Long Climb: From 1593 to 2772
The blitz rating history is a staircase with no landings. The file opens in May 2017 with a 1593 low and a 2305 close; two months later the high-water mark was 2420. The 2500s arrived in 2019, the 2600s by 2021, and the 2700 club in September 2025, capped by a 2772 (2026-02-13) recorded in February 2026. Along the way there was a 19-game winning streak, a 14-game losing streak, and presumably the same facial expression for both.
The Opening Repertoire: 1.d4 Forever
Looking for 1.e4 in this game collection? Bring a search party. In 2026, Sergey has opened with 1.d4 1,474 times and with 1.e4 exactly once. That lone king's pawn push is either a misclick, a prank, or an annual festival; either way, the queen's pawn opening is not a preference here, it is an identity.
As White, the favorite routes run through the King's Indian Defense: Accelerated Averbakh Variation, the most-played line in the collection at over 2,400 blitz games, plus mountains of Nimzo-Indian and Grunfeld structures. As Black, the paths get stranger: the Ruy Lopez: Brix Variation, a 43.9% win rate that functions as a personal haunted house, and the gloriously rude Blackburne Shilling Gambit, deployed 1,278 times against unsuspecting 1.e4 players.
The crown jewel is the Benoni Defense: King's Pawn Line: 1,652 games with a 62.35% win rate. When that pairing appears, the 62% usually has a name, and the name is on this page.
The skeleton of the whole operation, replayable below:
Rapid Perfection and the Bullet Incident
The records list Rapid as the preferred time control, and technically the evidence is airtight: five Rapid games, five wins, zero losses, a 2557 peak. That makes the record here statistically the most dominant, and thematically the most hilarious, achievement in the file. Undefeated champion of a format played for roughly one cumulative afternoon.
Then there is bullet chess, attempted exactly once, in June 2019. One game, one loss, one 1400 rating. Some people know their limits. Sergey learned that particular limit in about three minutes and retired from bullet with a spotless "never played again" record.
The Nemesis Wing
Every volume grinder accumulates specific humans who seem to own the head-to-head file. Chief among them is Alan Stein, against whom 187 games have produced 72 wins, 102 losses and 13 draws. That is not a rivalry; that is a subscription. The rare bright spot is Luis Galego, where a 100-game series finished 53-45-2 in Sergey's favor, living proof that even a nemesis can be worn down with enough rematches.
Style, Habits and the 5 AM Queue
- Best hour of the day: 5:00 AM, where the win rate peaks. Insomnia or discipline, the 5 AM lobby fears this account.
- Best weekday: Thursday. Saturdays are apparently when the sharks log on.
- Most common checking piece: the queen, by a landslide, with 40,115 career queen checks.
- Tilt factor: a remarkably calm 14. Losing streaks do not compound here; the next game is simply queued.
- Median opening preparation depth: 8 to 9 moves of theory, every single game.
The Career Ledger
- Rated blitz games: 46,969 (21,048 W, 21,792 L, 4,129 D)
- Longest winning streak: 19 games
- Longest losing streak: 14 games, which was clearly survived
- Games reaching an endgame: 85.7%
- Comeback rate: 89.8%
- Direct checkmate deliveries: statistically negligible, because opponents tend to resign first, which counts as a compliment
The summary: a FIDE Master with a classical title and a thoroughly online soul, someone who turned repetition into mastery, 1.d4 into destiny, and 47,000 games into a career that is still not finished. If the profile could speak, it would say what it always says: play 1.d4, survive the middlegame, grind the endgame, repeat until 2027.