Gustavo Horokoski De Souza, a.k.a. Horokoskii
Gustavo Horokoski De Souza, known to the online chess world as Horokoskii, is a National Master whose career is best described as an ultramarathon: long, steady, and fueled by stubbornness. Since his first rated games in April 2012, he has logged more than 17,000 games, the vast majority at bullet and blitz speed, and ground his way from a humble 1074 all the way to a peak blitz mark of 2407 (2026-02-17).
The Long Climb
The early years were a gentle uphill hike. A surge past 1500 blitz came in mid-2013, followed by a long, patient grind through the 1800s and 1900s. The 2000 barrier fell in late 2018, wobbled briefly in 2020, then held. The real fireworks arrived in 2025 and 2026, when Gustavo roared through the 2300s and touched 2407 blitz in February 2026, with a bullet peak of 2391 and a 2123 rapid peak along the way. Somewhere in there he also found time to earn the National Master title, presumably as a hobby.
A Life Devoted to the French
If you face Horokoskii, prepare to meet the French Defense. He has played it 325 times in blitz and another 874 in bullet, meeting 1.e4 with the calm of a man who has seen every trick twice. The French Defense: Exchange Variation is his best friend at a 59 percent win rate, the Advance Variation is a reliable soldier, and the Burn Variation is a coin flip he seems to enjoy losing occasionally. His one soft spot is the Tarrasch, Botvinnik Variation, where the win rate sinks to 39 percent. Aspiring giant-killers, take notes.
As White, Gustavo is a charming contrarian. He opens with 1.g4, the Australian Defense, at a 59.6 percent win rate, sprinkles in the Nimzo-Larsen Attack, and has played 2,484 bullet games of Colle system, including the gloriously named Rhamphorhynchus Variation, which sounds like a pterosaur and occasionally plays like one. In daily chess he becomes a final boss: 119 wins against only 14 losses, including a flawless 8 for 8 with the Barnes Defense and a perfect 13-0 in games where opening theory simply did not show up.
Style: Grind, Flag, Repeat
- Endgame animal: about 81 percent of his games reach deep endgames, and his wins average 78 moves. He does not blitz out victories, he slow-cooks them.
- Comeback artist: an 85 percent comeback rate and only about 1.5 percent one-sided losses. Dropping a piece to Horokoskii is not a verdict, it is an invitation.
- Graceful in defeat: most of his losses end in clean resignation. When it is lost, he tips the king and moves on.
- Flag collector: 3,829 wins by timeout. In bullet, the clock is a second, sharper queen.
- His favorite checking piece is the Queen, with more than 19,000 royal visits to the enemy king.
- Tilt factor of 13: cooler than the far side of the pillow.
- Circadian chess: best win rates at noon (about 59%) and midnight (about 55%), worst at 4pm (39%). Saturdays are treacherous at 44.6%, Sundays are blessed at 51.4%.
Rivals and Recurring Guests
Every grinder has a cast of regular sparring partners, and Gustavo's is colorful.
- matthewnotthemccounaughey is his most frequent dance partner at 94 games, and Gustavo leads 70-16-8. That is less a rivalry than a subscription.
- avellanedagg has taken 64 swings, losing 40 times against 17 wins and 7 draws.
- amillaneza trails 28-11-2 over 41 games, a polite beating.
- Sunjay Somani sits at 19-21-2 against him. Against Horokoskii, the username becomes purely aspirational.
- kamran SHIRAZI is the true nemesis: 15-23-3 over 41 games, the rare human who wins this matchup more often than not.
- babased stands dead even at 11-11-4, perfectly balanced, as all things should be.
The Career Ledger
- Blitz: 2,639 wins, 2,314 losses, 419 draws. Home turf.
- Bullet: 5,831 wins, 5,632 losses, 696 draws. More than 12,000 games of pure adrenaline.
- Rapid: 59 wins, 33 losses, 15 draws.
- Daily: 119 wins, 14 losses, 10 draws. The rare format where Horokoskii does the farming.
- Longest winning streak: 18 games. Longest losing streak: 13, quickly forgiven.
- 1,979 wins by checkmate and counting, with thousands more won on time.