Avatar of Marek Zakrzewski

Marek Zakrzewski FM

Username: Cosi43

Playing Since: 2019-08-15 (Inactive)

Wow Factor: ♟♟♟♟

Chess.com

Blitz: 2735
967W / 626L / 183D
Bullet: 2616
70W / 51L / 4D

Marek Zakrzewski — FIDE Master & Tactical Maestro

Marek Zakrzewski, aka Cosi43 to those who know him only from the chessboard, is no ordinary player – he’s a FIDE Master with a flair for blitz and bullet chess that can only be described as lightning-fast wizardry. Starting his blitz journey back in 2019 with a rating that sprinted from 1965 all the way up to a blistering 2739 by 2025, Marek’s growth resembles a rocket fueled by caffeine and sheer determination.

His blitz performance speaks volumes: over 1,500 games with an impressive 55%+ win rate, including a streak of 11 consecutive victories at one point. When Marek's on a roll (which is pretty often), his psychological resilience shines, boasting a comeback rate of nearly 94% and a perfect 100% win rate after losing a piece. Clearly, losing pieces is just a plot twist in his epic chess narratives.

If you’re playing against Marek on a Sunday afternoon (his best day according to stats), don’t be surprised if you’re caught off guard by his strategic endgames — he prefers the grind, with an endgame frequency of 87% and matches often stretching over 85 moves on average. Opponents like gmboorchess and newchess1213 have felt his wrath firsthand, with Marek boasting a perfect 100% win rate against them recently.

Marek also moonlights in bullet chess, proving that speed doesn’t come at the cost of accuracy. His bullet peak rating soared to 2693 in 2023, and he keeps a solid 56% win rate overall. Just don’t try to outpace him at the crack of dawn — his 6 AM win rate is a staggering 71%, suggesting that Marek is either a morning person or a chess ninja who sneaks games before sunrise.

Off the board, Marek might chuckle at the idea of "early resignation" since his rate is a modest 0.33% — talk about persistence! Whether wielding White or Black, he edges out a victory about half the time, proving adaptability and balance in his playstyle.

In summary, Marek Zakrzewski is a fierce competitor with a knack for turning tricky situations into victories, a chess player not just playing moves but weaving stories on 64 squares — watch out, world; this FM’s just getting started!


Coach Chesswick's Profile Photo
Coach Chesswick

Feedback for Marek Zakrzewski

Hi Marek, I've reviewed some of your recent games and here are a few observations and suggestions that can help you improve further:

Opening Phase

You demonstrate solid opening preparation, especially in the Sicilian structures and Pirc/Modern setups. Your moves like c3, d4, and careful development of minor pieces show good understanding. Keep deepening your knowledge of key ideas in your favorite openings, including typical pawn breaks and piece placements, as this will give you an edge in the early game.

Middle Game

You handle complex middle-game positions well, especially in juggling tension and strategic plans. Your active rook and bishop play in recent wins showed good coordination. However, there were moments where more precise calculation could help, particularly in dynamic positions with exchanges — try to always evaluate the consequences before committing to trades.

Endgame Technique

Your endgame technique is promising but can be sharpened by focusing on key principles like king activity, pawn structure weaknesses, and opposition. In one loss, a slight misstep in king maneuvering allowed the opponent to convert. Studying classic endgames and practicing basic theoretical winning and drawn positions will greatly benefit you.

Time Management

In several games, you managed your clock quite well, avoiding severe time pressure. This is a valuable strength. Continue to practice managing your time so you can maintain a steady pace for calculation and strategy formulation, especially under blitz and rapid time controls.

Areas to Work On

  • Calculation Under Pressure: Work on visualizing combinations and tactical motifs to gain confidence in sharp positions.
  • Positional Understanding: Try to deepen your evaluation of imbalances such as weak pawns, piece activity, and open files to create long-term plans.
  • Opening Repertoire Refinement: Occasionally, minor inaccuracies in opening lines allowed your opponents to seize the initiative. Regular review of your most played openings can aid in spotting improvements.

Next Steps

Review your recent losses and wins by replaying critical moments to identify decision points. Use a chess engine as a coach rather than an answer key—explore why alternative moves might be better. Focus on both tactics and strategic concepts to round out your game.

Keep up the great work, Marek! Your dedication is evident. With consistent practice and study, you will continue to climb and refine your skills.



🆚 Opponent Insights

Recent Opponents
Rudi Olenik Campa 1W / 0L / 1D View
chessmegabomb 0W / 1L / 0D View
Most Played Opponents
cockroachdolly 15W / 15L / 0D View Games
javicio 11W / 9L / 0D View Games
kaazbe7 14W / 6L / 0D View Games
civilized-barbarian 7W / 10L / 1D View Games
Rasan04 4W / 8L / 2D View Games

Rating

Year Bullet Blitz Rapid Daily
2025 2616 2735
2024 2654
2023 2605 2605
2022 2661 2671
2021 2664 2000
2020 2187 2515
2019 2475
Rating by Year201920202021202220232024202527352187YearRatingBulletBlitz

Stats by Year

Year White Black Moves
2025 105W / 70L / 19D 106W / 73L / 18D 91.4
2024 127W / 68L / 24D 109W / 88L / 27D 92.2
2023 136W / 97L / 30D 134W / 106L / 20D 89.3
2022 64W / 55L / 16D 72W / 55L / 10D 93.6
2021 24W / 5L / 2D 21W / 6L / 2D 79.8
2020 56W / 21L / 9D 60W / 20L / 7D 82.5
2019 19W / 6L / 3D 18W / 10L / 3D 89.1

Openings: Most Played

Blitz Opening Games Wins Losses Draws Win Rate
Modern 123 70 47 6 56.9%
QGD: Chigorin, 3.cxd5 120 68 43 9 56.7%
Scandinavian Defense 84 41 33 10 48.8%
London System: Poisoned Pawn Variation 66 30 27 9 45.5%
Amazon Attack: Siberian Attack 56 33 16 7 58.9%
Sicilian Defense: Alapin Variation, Sherzer Variation 56 31 14 11 55.4%
French Defense 46 27 12 7 58.7%
Colle System: Rhamphorhynchus Variation 46 29 12 5 63.0%
Australian Defense 45 30 13 2 66.7%
Döry Defense 44 18 21 5 40.9%
Bullet Opening Games Wins Losses Draws Win Rate
Modern 8 6 2 0 75.0%
Scandinavian Defense 6 3 3 0 50.0%
Barnes Defense 6 2 4 0 33.3%
Amar Gambit 6 2 4 0 33.3%
Sicilian Defense 5 1 4 0 20.0%
Sicilian Defense: Alapin Variation 5 4 1 0 80.0%
Czech Defense 5 2 3 0 40.0%
Australian Defense 5 2 3 0 40.0%
Caro-Kann Defense 5 2 2 1 40.0%
Alekhine Defense 3 3 0 0 100.0%
Daily Opening Games Wins Losses Draws Win Rate
London System: Poisoned Pawn Variation 1 0 0 1 0.0%

🔥 Streaks

Streak Longest Current
Winning 11 0
Losing 8 0
🐞 Report a Problem