75 games in the PremovedPrep archive. Games as White.
| White | Black | Result | ECO | Event | Date |
|---|---|---|---|---|---|
| Koska, Jiri | Mandak, Miroslav | 1-0 | A05 | exe: Slovakia chess open # Piešťany 2026 | 2026-07-16 |
| Koska, Jiri | Ruggiero, Chance Timothy | 1-0 | A34 | exe: Slovakia chess open # Piešťany 2026 | 2026-07-13 |
| Koska, Jiri | Jares, Michal | 0-1 | A34 | exe: Slovakia chess open # Piešťany 2026 | 2026-07-11 |
| Koska, Jiri | Kollarik, Gorazd | 1-0 | A34 | exe: Slovakia chess open # Piešťany 2026 | 2026-07-09 |
| Koska, Jiri | Klimanek, Daniel | 1-0 | E63 | Piestany | 2025-07-15 |
| Koska, Jiri | Muller, Tomas | 1-0 | A01 | Piestany | 2025-07-13 |
| Koska, Jiri | Durana, Jonas | 1/2-1/2 | A45 | Piestany | 2025-07-07 |
| Koska, Jiri | Jura, Michal | 1/2-1/2 | C42 | goral | 2024-09-09 |
| Koska, Jiri | Danada, Tomas | 1-0 | A06 | goral | 2024-09-08 |
| Koska, Jiri | Verba, Vladimir | 1/2-1/2 | A06 | goral | 2024-09-07 |
| Koska, Jiri | Duda, Daniel | 1-0 | A05 | goral | 2024-09-06 |
| Koska, Jiri | Har-Even, Abir | 1/2-1/2 | A04 | Slovakia chess open PN 24 | 2024-07-15 |
| Koska, Jiri | Siraj, Anej | 1-0 | A13 | Slovakia chess open PN 24 | 2024-07-13 |
| Koska, Jiri | Bednar, Jan | 1-0 | A07 | Slovakia chess open PN 24 | 2024-07-11 |
| Koska, Jiri | Ostruzlik, Kristian | 1/2-1/2 | A05 | MSR amaterov | 2024-06-18 |
| Koska, Jiri | Zvarik, Martin | 0-1 | C50 | MSR amaterov | 2024-06-17 |
| Koska, Jiri | Zentko, Ladislav | 1/2-1/2 | C54 | MSR amaterov | 2024-06-16 |
| Koska, Jiri | Foldesi, Jan | 1-0 | A05 | MSR amaterov | 2024-06-15 |
| Koska, Jiri | Samu, Sorin-Mihai | 1/2-1/2 | A04 | Reinter Open | 2024-06-08 |
| Koska, Jiri | Shykhnenko, Hryhorii | 0-1 | A05 | MSR DL | 2023-10-28 |
| Koska, Jiri | Lovcican, Tomas | 0-1 | A05 | Dorastenecka liga | 2023-10-27 |
| Koska, Jiri | Bilik, Matej | 1/2-1/2 | A38 | Dorastenecka liga | 2023-10-26 |
| Koska, Jiri | Skrbec, Leon | 0-1 | A05 | 22nd European Youth Blitz Championship 2023 - O-16 | 2023-09-30 |
| Koska, Jiri | Rybka, Simon | 0-1 | A04 | MSR 2023 Blitz | 2023-09-09 |
| Koska, Jiri | Kuznecova, Marija | 0-1 | A07 | WSTC | 2023-08-07 |
| Koska, Jiri | Ahnaf Rashid, Chowdhury | 1-0 | B47 | WSTC | 2023-08-06 |
| Koska, Jiri | Morocho Garzon, Fernando Jose | 1-0 | A08 | WSTC | 2023-08-05 |
| Koska, Jiri | Andziswa, Hlophe | 1-0 | C41 | WSTC | 2023-08-04 |
| Koska, Jiri | Chrz, Pavel | 0-1 | A04 | rapid | 2022-07-21 |
| Koska, Jiri | Vokoun, Jan | 1-0 | A04 | rapid | 2022-07-20 |
| Koska, Jiri | Akesson, Ralf | 0-1 | A05 | rapid | 2022-07-20 |
| Koska Jiri | Kulich Daniel | 1-0 | A04 | LJ Slovak Open 2022 | 2022-06-26 |
| Koska Jiri | Hurtuk Radovan | 0-1 | B90 | LJ Slovak Open 2022 | 2022-06-24 |
| Koska Jiri | Janik Marek Tobias | 0-1 | D02 | MSR deti a mladeze | 2022-05-27 |
| Koska Jiri | Baron Patrik | 1/2-1/2 | A07 | MSR deti a mladeze | 2022-05-25 |
| Koska Jiri | Orgon Patrik | 1/2-1/2 | A13 | MSR deti a mladeze | 2022-05-23 |
| Koska Jiri | Sandor Samuel | 0-1 | C55 | MSR deti a mladeze | 2022-05-22 |