| Game |
| Result | Moves |
Year | Event/Locale | Opening |
| 176. F Izeta Txabarri vs M Sion Castro |
| ½-½ | 55 | 1997 | Elgoibar | E64 King's Indian, Fianchetto, Yugoslav System |
| 177. M Sion Castro vs J M Gomez Esteban |
| 0-1 | 51 | 1997 | Elgoibar | C70 Ruy Lopez |
| 178. C S Matamoros Franco vs M Sion Castro |
| ½-½ | 20 | 1997 | Elgoibar | D56 Queen's Gambit Declined |
| 179. M Sion Castro vs G Giorgadze |
| ½-½ | 16 | 1997 | Elgoibar | C95 Ruy Lopez, Closed, Breyer |
| 180. A Castany Pampalona vs M Sion Castro |
| 0-1 | 32 | 1998 | Spanish Championship | E90 King's Indian |
| 181. M Sion Castro vs J Cardenas Valero |
| 0-1 | 29 | 1998 | Spanish Championship | B33 Sicilian |
| 182. M Perez Candelario vs M Sion Castro |
| 0-1 | 43 | 1998 | Spanish Championship | B47 Sicilian, Taimanov (Bastrikov) Variation |
| 183. M Sion Castro vs P Ferrer Sanchez |
| 1-0 | 30 | 1998 | Spanish Championship | B87 Sicilian, Fischer-Sozin with ...a6 and ...b5 |
| 184. S Almagro Mazariegos vs M Sion Castro |
| ½-½ | 34 | 1998 | Spanish Championship | A15 English |
| 185. M Sion Castro vs N Garcia Vicente |
| 1-0 | 38 | 1998 | Spanish Championship | C67 Ruy Lopez |
| 186. L Comas Fabrego vs M Sion Castro |
| ½-½ | 9 | 1998 | Spanish Championship | D02 Queen's Pawn Game |
| 187. M Sion Castro vs J M Gomez Esteban |
| 1-0 | 46 | 1998 | Spanish Championship | C93 Ruy Lopez, Closed, Smyslov Defense |
| 188. S del Rio de Angelis vs M Sion Castro |
| ½-½ | 35 | 1998 | Spanish Championship | B47 Sicilian, Taimanov (Bastrikov) Variation |
| 189. M Sion Castro vs D Komljenovic |
| ½-½ | 10 | 1999 | Pamplona op | B08 Pirc, Classical |
| 190. M Sion Castro vs A Bayod Rubia |
| 1-0 | 60 | 1999 | Benasque Open | B45 Sicilian, Taimanov |
| 191. A Alonso Alvarez vs M Sion Castro |
| 0-1 | 62 | 1999 | Benasque Open | A49 King's Indian, Fianchetto without c4 |
| 192. M Sion Castro vs P Martinez Velert |
| 0-1 | 37 | 1999 | Benasque Open | B90 Sicilian, Najdorf |
| 193. J A Alcazar Jimenez vs M Sion Castro |
| 0-1 | 34 | 1999 | Benasque Open | B46 Sicilian, Taimanov Variation |
| 194. M Sion Castro vs B Latzke |
| 1-0 | 66 | 1999 | Benasque Open | C81 Ruy Lopez, Open, Howell Attack |
| 195. M Marin vs M Sion Castro |
| 1-0 | 37 | 1999 | Benasque Open | A33 English, Symmetrical |
| 196. M Sion Castro vs M Perez Candelario |
| 1-0 | 28 | 1999 | Benasque Open | E54 Nimzo-Indian, 4.e3, Gligoric System |
| 197. E Fernandez Romero vs M Sion Castro |
| 0-1 | 38 | 1999 | Benasque Open | B44 Sicilian |
| 198. M Sion Castro vs O Rodriguez Vargas |
| 1-0 | 17 | 1999 | Benasque Open | B01 Scandinavian |
| 199. A Veingold vs M Sion Castro |
| 1-0 | 41 | 1999 | ESP-chT Div 2 | D85 Grunfeld |
| 200. M Sion Castro vs R Molina Mansilla |
| 1-0 | 26 | 2001 | Spanish Team Championship 2nd Division | B50 Sicilian |
Kibitzing
