| Game |
| Result | Moves |
Year | Event/Locale | Opening |
| 1. Hodgson vs S Semkov |
| 0-1 | 40 | 1976 | World Championship (U17) | B33 Sicilian |
| 2. S Semkov vs F Wunderlich |
| 1-0 | 30 | 1976 | World Championship (U17) | E87 King's Indian, Samisch, Orthodox |
| 3. S Semkov vs L Arnold |
| 1-0 | 44 | 1976 | World Championship (U17) | A66 Benoni |
| 4. D Roos vs S Semkov |
| 0-1 | 44 | 1976 | World Championship (U17) | B25 Sicilian, Closed |
| 5. T Salen vs S Semkov |
| ½-½ | 23 | 1976 | World Championship (U17) | B20 Sicilian |
| 6. A Chia vs S Semkov |
| 1-0 | 35 | 1976 | World Championship (U17) | A77 Benoni, Classical, 9...Re8, 10.Nd2 |
| 7. S Semkov vs Van der Wiel |
| 0-1 | 35 | 1976 | World Championship (U17) | A33 English, Symmetrical |
| 8. S Semkov vs J Weber |
| 0-1 | 38 | 1976 | World Championship (U17) | A58 Benko Gambit |
| 9. S Semkov vs I Rogers |
| 0-1 | 27 | 1976 | World Championship (U17) | D07 Queen's Gambit Declined, Chigorin Defense |
| 10. S Semkov vs K Georgiev |
| 0-1 | 21 | 1977 | Varna | B96 Sicilian, Najdorf |
| 11. S Semkov vs J Pinter |
 | 1-0 | 41 | 1977 | Varna | C56 Two Knights |
| 12. I Radulov vs S Semkov |
| 1-0 | 29 | 1977 | BUL-ch | B45 Sicilian, Taimanov |
| 13. S Semkov vs C Arduman |
| 1-0 | 46 | 1977 | Albena Balkaniad (boys) | B67 Sicilian, Richter-Rauzer Attack, 7...a6 Defense, 8...Bd7 |
| 14. I Marasescu vs S Semkov |
| ½-½ | 42 | 1977 | Albena Balkaniad (boys) | A16 English |
| 15. S Semkov vs S Gekas |
| 1-0 | 32 | 1977 | Albena Balkaniad (boys) | E70 King's Indian |
| 16. G Dizdar vs S Semkov |
| 1-0 | 43 | 1977 | Albena Balkaniad (boys) | A05 Reti Opening |
| 17. D Donchev vs S Semkov |
| 1-0 | 45 | 1978 | Varna | B89 Sicilian |
| 18. S Semkov vs N Sulava |
| ½-½ | 56 | 1979 | Balkaniad U20 11th | A54 Old Indian, Ukrainian Variation, 4.Nf3 |
| 19. Hadeler vs S Semkov |
| 0-1 | 35 | 1979 | Balkaniad 11 U20 | B89 Sicilian |
| 20. S Semkov vs J Nogueiras |
| 1-0 | 57 | 1982 | Varna Golden Sands | D33 Queen's Gambit Declined, Tarrasch |
| 21. Savon vs S Semkov |
| 1-0 | 56 | 1982 | Varna Golden Sands | D32 Queen's Gambit Declined, Tarrasch |
| 22. D Donchev vs S Semkov |
| 1-0 | 50 | 1982 | Varna Golden Sands | B76 Sicilian, Dragon, Yugoslav Attack |
| 23. S Semkov vs J Grigorov |
| 0-1 | 42 | 1982 | Varna Golden Sands | E77 King's Indian |
| 24. S Semkov vs P Stefanov |
| 1-0 | 55 | 1982 | Varna Golden Sands | E42 Nimzo-Indian, 4.e3 c5, 5.Ne2 (Rubinstein) |
| 25. S Semkov vs M Garkov |
| 0-1 | 57 | 1982 | Varna Golden Sands | B06 Robatsch |
Kibitzing
