| Jun 27, 2026 | Wolak | 1–0 | Siennicki | Macieja Memorial | Rapport-Jobava System | |
| Jun 27, 2026 | Siennicki | 1–0 | Leniart | Macieja Memorial | Bogo-Indian Defense: Retreat Variation | |
| Jun 27, 2026 | Siennicki | 0–1 | Wasiluk | Macieja Memorial | ? | |
| Jun 27, 2026 | Pechac | 1–0 | Siennicki | Macieja Memorial | ? | |
| Jul 16, 2025 | Goderdzishvili | 0–1 | Siennicki | Najdorf Memorial | Caro-Kann Defense: Karpov Variation, Modern Variation, Kasparov Attack | |
| Jul 16, 2025 | Siennicki | 0–1 | Borowy | Najdorf Memorial | Zukertort Opening: Pirc Invitation | |
| Jul 15, 2025 | Witczak | 1–0 | Siennicki | Najdorf Memorial | Nimzo-Indian Defense: Normal Variation | |
| Jul 14, 2025 | Siennicki | ½–½ | Cornelisse | Najdorf Memorial | Queen's Pawn Game: Accelerated London System, Steinitz Countergambit | |
| Jul 13, 2025 | Siennicki | ½–½ | Zysko | Najdorf Memorial | Slav Defense: Modern Line | |
| Jul 13, 2025 | Suska | 1–0 | Siennicki | Najdorf Memorial | English Opening: Anglo-Indian Defense, King's Knight Variation | |
| Jul 11, 2025 | Arnold | 1–0 | Siennicki | Najdorf Memorial | Caro-Kann Defense: Advance Variation, Short Variation | |
| Jul 10, 2025 | Siennicki | ½–½ | Szewczyk | Najdorf Memorial | Catalan Opening: Closed, Main Line | |
| Jul 8, 2025 | Siennicki | ½–½ | Chomczyk | Najdorf Memorial | Indian Defense: Pseudo-Benko | |
| Apr 9, 2025 | Solnicki | 1–0 | Siennicki | Columbus Mistrzostwa Polski Amatorów - do 2200 FIDE | Caro-Kann Defense: Tartakower Variation | |
| Apr 8, 2025 | Siennicki | 1–0 | Siennicki | Columbus Mistrzostwa Polski Amatorów - do 2200 FIDE | Queen's Pawn Game: Symmetrical Variation | |
| Apr 7, 2025 | Wodniczak | 1–0 | Siennicki | Columbus Mistrzostwa Polski Amatorów - do 2200 FIDE | King's Indian Attack | |
| Apr 6, 2025 | Siennicki | 1–0 | Paziak | Columbus Mistrzostwa Polski Amatorów - do 2200 FIDE | Indian Defense: Pseudo-Benko | |
| Apr 5, 2025 | Plotka | ½–½ | Siennicki | Columbus Mistrzostwa Polski Amatorów - do 2200 FIDE | Yusupov-Rubinstein System | |
| Feb 9, 2025 | Kondys | 1–0 | Siennicki | Open A | Caro-Kann Defense: Exchange Variation | |
| Feb 8, 2025 | Siennicki | 1–0 | Figa | Open A | Catalan Opening: Closed | |
| Feb 8, 2025 | Kawka | 1–0 | Siennicki | Open A | Caro-Kann Defense: Advance Variation, Tal Variation | |
| Feb 7, 2025 | Siennicki | 1–0 | Kaminska | Open A | Indian Defense | |
| Feb 6, 2025 | Siennicki | ½–½ | Serafin | Open A | Catalan Opening: Closed | |
| Feb 6, 2025 | Owczarek | 0–1 | Siennicki | Open A | English Opening: Anglo-Indian Defense, Nimzo-English | |
| Feb 5, 2025 | Siennicki | ½–½ | Jedynak | A | Catalan Opening: Closed | |
| Feb 4, 2025 | Siennicki | 1–0 | Smolka | A | Queen's Gambit Declined | |
| Feb 4, 2025 | Kulpinski | 0–1 | Siennicki | A | Bogo-Indian Defense: Grünfeld Variation | |
| Feb 3, 2025 | Trybus | 1–0 | Siennicki | A | English Opening: Agincourt Defense | |
| Sep 8, 2024 | Zielinski | 0–1 | Siennicki | 2liga-2 | Caro-Kann Defense: Two Knights Attack | |
| Sep 7, 2024 | Siennicki | ½–½ | Majocha | 2liga-2 | Nimzo-Larsen Attack: Indian Variation | |
| Sep 6, 2024 | Maj | 1–0 | Siennicki | DMP II LIga 2024 1 | Zukertort Opening: Reversed Grünfeld | |
| Sep 5, 2024 | Siennicki | ½–½ | Flis | 2liga-2 | Indian Defense: London System | |
| Sep 4, 2024 | Siennicki | 1–0 | Kupryjaniuk | 2liga-2 | Pirc Defense | |
| Sep 3, 2024 | Kraczek | 1–0 | Siennicki | 2liga-2 | Caro-Kann Defense: Maróczy Variation | |
| Sep 2, 2024 | Rekuc | 1–0 | Siennicki | DMP II LIga 2024 1 | Bogo-Indian Defense: Nimzowitsch Variation | |
| Sep 1, 2024 | Siennicki | ½–½ | Krol | 2liga-2 | Catalan Opening | |
| Aug 31, 2024 | Przerwa | ½–½ | Siennicki | DMP II LIga 2024 1 | Petrov's Defense: Nimzowitsch Attack | |
| Aug 25, 2024 | Siennicki | 0–1 | Ramakrishnan M R | rubinstein24-a1 | Catalan Opening: Closed | |
| Aug 24, 2024 | Matela | ½–½ | Siennicki | rubinstein24-a1 | Caro-Kann Defense: Endgame Offer | |
| Aug 23, 2024 | Siennicki | 1–0 | Motyl | rubinstein24-a1 | Benoni Defense: Old Benoni | |
| Aug 22, 2024 | Ochedzan | 1–0 | Siennicki | rubinstein24-a1 | Caro-Kann Defense: Tartakower Variation | |
| Aug 21, 2024 | Ciolek | ½–½ | Siennicki | rubinstein24-a1 | Nimzo-Indian Defense: Classical Variation, Noa Variation | |
| Aug 20, 2024 | Siennicki | 1–0 | Aadith R | rubinstein24-a1 | Catalan Opening: Closed | |
| Aug 19, 2024 | Siennicki | 0–1 | Rzeszowski | rubinstein24-a1 | Dutch Defense: Staunton Gambit | |
| Aug 18, 2024 | Majocha | 1–0 | Siennicki | rubinstein24-a1 | English Opening: Anglo-Indian Defense, Nimzo-English | |
| Aug 17, 2024 | Siennicki | 0–1 | Cernov | rubinstein24-a1 | Mexican Defense | |
| Jul 17, 2024 | Jurasz | ½–½ | Siennicki | Najdorf Memorial | Caro-Kann Defense: Tartakower Variation | |
| Jul 16, 2024 | Siennicki | 0–1 | Harazinska | Najdorf Memorial | Queen's Pawn Game: Accelerated London System | |
| Jul 15, 2024 | Lasota | ½–½ | Siennicki | Najdorf Memorial | Indian Defense | |
| Jul 14, 2024 | Hury | 1–0 | Siennicki | Najdorf Memorial | Caro-Kann Defense: Advance Variation, Short Variation | |
| Jul 13, 2024 | Siennicki | 0–1 | Tsiapko | Najdorf Memorial | Catalan Opening: Closed, Botvinnik Variation | |
| Jul 12, 2024 | Siennicki | 1–0 | Bednarska-Bzdega | Najdorf Memorial | Neo-Grünfeld Defense: Exchange Variation | |
| Jul 11, 2024 | Delega | ½–½ | Siennicki | Najdorf Memorial | Caro-Kann Defense: Tartakower Variation | |
| Jul 10, 2024 | Chmiel | 1–0 | Siennicki | Najdorf Memorial | English Opening: Agincourt Defense | |
| Jul 9, 2024 | Siennicki | 0–1 | Kowalczyk | Najdorf Memorial | Catalan Opening: Open Defense, Classical Line | |
| May 4, 2024 | Siennicki | 0–1 | Golubka | Round 7: Siennicki, Gustaw - Golubka, Petro | Dutch Defense: Staunton Gambit, Chigorin Variation | |
| May 3, 2024 | Chomczyk | ½–½ | Siennicki | Round 6: Chomczyk, Marek - Siennicki, Gustaw | Caro-Kann Defense: Two Knights Attack | |
| May 3, 2024 | Iwanczuk | 0–1 | Siennicki | Round 5: Iwanczuk, Krzysztof - Siennicki, Gustaw | King's Indian Attack: Symmetrical Defense | |
| May 2, 2024 | Siennicki | 1–0 | Haliniak | Round 4: Siennicki, Gustaw - Haliniak, Wojciech | Dutch Defense: Staunton Gambit, Chigorin Variation | |
| May 2, 2024 | Bartosz Przybylski | ½–½ | Siennicki | Round 3: Bartosz Przybylski - Siennicki, Gustaw | Caro-Kann Defense: Advance Variation, Tal Variation | |
| May 1, 2024 | Siennicki | * | Tomasz Kaczmarek | Round 2: Siennicki, Gustaw - Tomasz Kaczmarek | ? | |
| May 1, 2024 | Perz | * | Siennicki | Round 1: Perz, Ignacy - Siennicki, Gustaw | ? | |
| — | Siennicki | ½–½ | Rog | C18 | Nimzowitsch Defense: Scandinavian Variation, Advance Variation | |
| — | Siennicki | 1–0 | Rog | C18b | Nimzowitsch Defense: Scandinavian Variation, Advance Variation | |
| — | Siennicki | 1–0 | Janeczko | C18b | Indian Defense: Spielmann-Indian | |
| — | Siennicki | 0–1 | Malek | C18b | Indian Defense: Wade-Tartakower Defense | |
| — | Siennicki | 1–0 | Kusiak | C18b | Indian Defense: Spielmann-Indian | |
| — | Siennicki | ½–½ | Fiszer | C18b | Indian Defense: Wade-Tartakower Defense | |
| — | Siennicki | 0–1 | Dziewonski | C18b | Catalan Opening: Closed | |
| — | Siennicki | 0–1 | Chmielek | Rubinstein Chess Festival 2025 - OPEN A | Catalan Opening: Closed | |
| — | Siennicki | 0–1 | Ciupka | Rubinstein Chess Festival 2025 - OPEN A | French Defense: McCutcheon Variation, Lasker Variation | |
| — | Siennicki | 0–1 | Wandor | Rubinstein Chess Festival 2025 - OPEN A | ? | |
| — | Malek | 1–0 | Siennicki | C18 | Trompowsky Attack: Classical Defense, Big Center Variation | |
| — | Radzimski | 0–1 | Siennicki | C18b | Nimzo-Indian Defense: Normal Variation | |
| — | Grzebieniowski | 0–1 | Siennicki | C18b | Bogo-Indian Defense: Nimzowitsch Variation | |
| — | Musial | ½–½ | Siennicki | C18b | Caro-Kann Defense: Advance Variation | |
| — | Madej | ½–½ | Siennicki | C18b | Caro-Kann Defense: Advance Variation, Van der Wiel Attack | |
| — | Borischik | ½–½ | Siennicki | C18b | King's Indian Attack | |
| — | Napieralski | 1–0 | Siennicki | Rubinstein Chess Festival 2025 - OPEN A | Caro-Kann Defense: Exchange Variation | |
| — | Zeissel | ½–½ | Siennicki | Rubinstein Chess Festival 2025 - OPEN A | Modern Defense: Lizard Defense, Mittenberger Gambit | |