| 14 ago 2026 | Lavrencic, Matic 2490 | Sieciechowicz, Marcin 2377 | 1-0 | C54 Apertura Italiana: Classical Variation, Giuoco Pianissimo | Spilimbergo Master 2026 | 94 | Ver |
| 13 ago 2026 | Sieciechowicz, Marcin 2377 | Roshka, Yevgeniy 2479 | 0-1 | A05 Ataque Indio de Rey | Spilimbergo Master 2026 | 55 | Ver |
| 12 ago 2026 | Martinovici, Ilia 2480 | Sieciechowicz, Marcin 2377 | ½-½ | C22 Apertura del Centro: Berger Variation | Spilimbergo Master 2026 | 105 | Ver |
| 11 ago 2026 | Sieciechowicz, Marcin 2377 | Maksimovic, Bojan 2537 | ½-½ | E68 Defensa India de Rey: Fianchetto Variation, Classical Variation | Spilimbergo Master 2026 | 22 | Ver |
| 10 ago 2026 | Santiago, Yago De Moura 2493 | Sieciechowicz, Marcin 2377 | 0-1 | D43 Defensa Semieslava | Spilimbergo Master 2026 | 58 | Ver |
| 1 ago 2026 | Smeryk, Andriy 2172 | Sieciechowicz, Marcin 2356 | 0-1 | A01 Ataque Nimzo-Larsen: Modern Variation | anderssenRAPID | 74 | Ver |
| 1 ago 2026 | Sieciechowicz, Marcin 2356 | Haladaj, Adam 2084 | 1-0 | D35 Gambito de Dama rehusado: Exchange Variation, Positional Variation | anderssenRAPID | 62 | Ver |
| 1 jul 2026 | Rekuc, Patryk 2216 | Sieciechowicz, Marcin 2391 | 1-0 | D11 Defensa Eslava: Quiet Variation, Pin Defense | Najdorf Memorial | 40 | Ver |
| 30 jun 2026 | Sieciechowicz, Marcin 2386 | Tytynnik, Artem 2212 | ½-½ | A07 Ataque Indio de Rey: Pachman System | Najdorf Memorial | 88 | Ver |
| 29 jun 2026 | Sprzeczka, Emilia 2105 | Sieciechowicz, Marcin 2386 | 0-1 | D14 Defensa Eslava: Exchange Variation, Symmetrical Line | Najdorf Memorial | 37 | Ver |
| 28 jun 2026 | Sieciechowicz, Marcin 2386 | Sujkowski, Pawel 2059 | ½-½ | D26 Gambito de Dama aceptado: Normal Variation, Traditional System | Najdorf Memorial | 43 | Ver |
| 27 jun 2026 | Zajac, Szymon 2072 | Sieciechowicz, Marcin 2386 | ½-½ | A07 Ataque Indio de Rey: Double Fianchetto | Najdorf Memorial | 33 | Ver |
| 27 jun 2026 | Sieciechowicz, Marcin 2326 | Mulawa, Cyprian 2245 | 1-0 | D35 Gambito de Dama rehusado: Exchange Variation, Positional Variation | Macieja Memorial | 39 | Ver |
| 27 jun 2026 | Krzyzanowski, Marcin 2467 | Sieciechowicz, Marcin 2326 | 1-0 | A05 Apertura Zukertort: Nimzo-Larsen Variation | Macieja Memorial | 45 | Ver |
| 27 jun 2026 | Sieciechowicz, Marcin 2326 | Kazakouski, Valery 2546 | 1-0 | A41 Defensa Rata: English Rat | Macieja Memorial | 45 | Ver |
| 27 jun 2026 | Terkiewicz, Bruno 2174 | Sieciechowicz, Marcin 2326 | 0-1 | D82 Defensa Grünfeld: Brinckmann Attack | Macieja Memorial | 44 | Ver |
| 27 jun 2026 | Sieciechowicz, Marcin 2326 | Socko, Monika 2169 | 1-0 | E32 Defensa Nimzoindia: Classical Variation | Macieja Memorial | 51 | Ver |
| 27 jun 2026 | Kubicka, Anna 2049 | Sieciechowicz, Marcin 2326 | 1-0 | B20 Defensa Siciliana: Keres Variation | Macieja Memorial | 53 | Ver |
| 27 jun 2026 | Sieciechowicz, Marcin 2326 | Backiel, Hubert 2141 | 1-0 | D31 Defensa Semieslava: Marshall Gambit, Forgotten Variation | Macieja Memorial | 31 | Ver |
| 27 jun 2026 | Stachniak, Stanislaw 2063 | Sieciechowicz, Marcin 2326 | 0-1 | A05 Apertura Zukertort: Nimzo-Larsen Variation | Macieja Memorial | 35 | Ver |