| Game |
| Result | Moves |
Year | Event/Locale | Opening |
| 251. A Krainski vs M Olszewski |
| 0-1 | 28 | 2017 | European Blitz Championship | B92 Sicilian, Najdorf, Opocensky Variation |
| 252. M Olszewski vs A Krainski |
| ½-½ | 43 | 2017 | European Blitz Championship | C65 Ruy Lopez, Berlin Defense |
| 253. M Olszewski vs D Sliwicki |
| 1-0 | 43 | 2017 | European Blitz Championship | B30 Sicilian |
| 254. D Sliwicki vs M Olszewski |
| 0-1 | 65 | 2017 | European Blitz Championship | B53 Sicilian |
| 255. W Klepek vs M Olszewski |
| 0-1 | 35 | 2017 | European Blitz Championship | B90 Sicilian, Najdorf |
| 256. M Olszewski vs W Klepek |
| 1-0 | 59 | 2017 | European Blitz Championship | C11 French |
| 257. M Olszewski vs D Mastrovasilis |
| 0-1 | 38 | 2017 | European Blitz Championship | B47 Sicilian, Taimanov (Bastrikov) Variation |
| 258. D Mastrovasilis vs M Olszewski |
| ½-½ | 28 | 2017 | European Blitz Championship | B54 Sicilian |
| 259. D Janaszak vs M Olszewski |
| 0-1 | 34 | 2017 | European Blitz Championship | A45 Queen's Pawn Game |
| 260. M Olszewski vs D Janaszak |
| 1-0 | 30 | 2017 | European Blitz Championship | B30 Sicilian |
| 261. M Olszewski vs D Lewtak |
| 0-1 | 34 | 2017 | European Blitz Championship | B00 Uncommon King's Pawn Opening |
| 262. I Gazik vs M Olszewski |
| 0-1 | 12 | 2017 | European Blitz Championship | A07 King's Indian Attack |
| 263. M Olszewski vs I Gazik |
| 1-0 | 42 | 2017 | European Blitz Championship | C07 French, Tarrasch |
| 264. M Olszewski vs K Jakubowski |
| 0-1 | 28 | 2017 | European Blitz Championship | B80 Sicilian, Scheveningen |
| 265. K Jakubowski vs M Olszewski |
| 1-0 | 60 | 2017 | European Blitz Championship | A48 King's Indian |
| 266. S Sahidi vs M Olszewski |
| 0-1 | 52 | 2017 | European Blitz Championship | A00 Uncommon Opening |
| 267. M Olszewski vs S Sahidi |
 | 1-0 | 42 | 2017 | European Blitz Championship | B12 Caro-Kann Defense |
| 268. M Olszewski vs K Schulz |
| 1-0 | 35 | 2017 | European Blitz Championship | B07 Pirc |
| 269. K Schulz vs M Olszewski |
| 1-0 | 45 | 2017 | European Blitz Championship | A05 Reti Opening |
| 270. M Olszewski vs Aleksander Kus |
| 1-0 | 24 | 2017 | European Rapid Championship | C18 French, Winawer |
| 271. M Orndahl vs M Olszewski |
| 0-1 | 21 | 2017 | European Rapid Championship | A45 Queen's Pawn Game |
| 272. M Olszewski vs P Piotrowski |
| 1-0 | 51 | 2017 | European Rapid Championship | B56 Sicilian |
| 273. R Klabis vs M Olszewski |
| 1-0 | 38 | 2017 | European Rapid Championship | B51 Sicilian, Canal-Sokolsky (Rossolimo) Attack |
| 274. M Olszewski vs K Tomaszewski |
| 1-0 | 52 | 2017 | European Rapid Championship | B47 Sicilian, Taimanov (Bastrikov) Variation |
| 275. S Zaksaite vs M Olszewski |
| 1-0 | 50 | 2017 | European Rapid Championship | B90 Sicilian, Najdorf |
Kibitzing
