Kim Sergey: FIDE Master and Blitz Marathoner
Meet Kim Sergey
Kim Sergey, known online as sergeikim, is a FIDE Master with a simple online philosophy: play an enormous amount of blitz, ideally at five in the morning. His best time of day to play is reportedly 05:00, which should worry anyone who logs on for a casual early-morning game.
With nearly 47,000 rated games to his name, Kim has built an online empire one 1.d4 at a time. He is not a dabbler; he is a volume shooter, and the volume is almost entirely blitz.
Career Journey
Kim's blitz rating history is a long, rewarding climb. From the low 2300s in 2017, he pushed steadily upward, reaching a peak of 2772 (2026-02-13). The path was not perfectly smooth, but the trend tells the story: he kept improving.
His white repertoire is built around 1.d4, and he frequently lands in the King's Indian Defense and Nimzo-Indian Defense with the confidence of someone who has seen just about every trap. As Black against 1.e4, he often emerges into the Ruy Lopez, where he grinds out long and stubborn battles.
Playing Style
Kim does not play hurried, careless blitz. Almost 86 percent of his games reach an endgame, and his wins average around 75 moves. He rarely resigns early, and his comeback rate is nearly 90 percent, so an opponent holding a material advantage should not start celebrating too soon.
He is noticeably stronger with the white pieces, winning around 47 percent of those games compared with around 43 percent as Black. That may not sound enormous, but in a sea of tens of thousands of games, it is the kind of edge that separates a titled grinder from everyone else.
Rivalries
No biography of Kim Sergey would be complete without his favorite rivals. The most intense online feud is with Alan Stein, who faced Kim in a jaw-dropping 187 games. Aliencowboy holds the narrow edge in their marathon series, winning 102 times to Kim's 72, with 13 draws. Kim has also traded hundreds of games with Nathan White; their 130-game series is also fiercely contested. He keeps coming back for more, which says a lot about his durability.
Rapid and Other Curiosities
Despite being essentially a blitz specialist, Kim's profile states that his preferred time control is Rapid. In his tiny rated rapid sample, he is perfect: five wins and no losses. It is a small sample, but it gives off a happy undefeated because barely played vibe. Meanwhile, his single bullet game remains a loss, a blemish he seems determined never to repeat.