Game |
| Result | Moves |
Year | Event/Locale | Opening |
1. Shamkovich vs T Thorhallsson |
| 1-0 | 28 | 1984 | Reykjavik Open | A96 Dutch, Classical Variation |
2. T Bjornsson vs T Thorhallsson |
| 0-1 | 36 | 1984 | Reykjavik Open | C50 Giuoco Piano |
3. Blatny vs T Thorhallsson |
| 1-0 | 40 | 1986 | EU-ch U20 | B01 Scandinavian |
4. T Thorhallsson vs Blatny |
| ½-½ | 31 | 1986 | Wch U20 | C56 Two Knights |
5. Arencibia Rodriguez vs T Thorhallsson |
| ½-½ | 61 | 1986 | Wch U20 | D31 Queen's Gambit Declined |
6. Anand vs T Thorhallsson |
| 1-0 | 39 | 1986 | Wch U20 | B57 Sicilian |
7. Ivanchuk vs T Thorhallsson |
| 1-0 | 37 | 1987 | Wch U20 | D30 Queen's Gambit Declined |
8. T Thorhallsson vs Hertneck |
| 0-1 | 48 | 1987 | Gausdal Int | C10 French |
9. T Thorhallsson vs Blatny |
| 0-1 | 56 | 1987 | Wch U20 | C60 Ruy Lopez |
10. T Thorhallsson vs Flear |
 | 1-0 | 61 | 1987 | 11th Lloyds Bank Masters Open | C54 Giuoco Piano |
11. T Thorhallsson vs Fedorowicz |
 | 0-1 | 24 | 1987 | 11th Lloyds Bank Masters Open | B22 Sicilian, Alapin |
12. Anand vs T Thorhallsson |
| 1-0 | 43 | 1987 | 11th Lloyds Bank Masters Open | C04 French, Tarrasch, Guimard Main line |
13. T Thorhallsson vs G Runarsson |
| 1-0 | 42 | 1987 | ISL-ch | D74 Neo-Grunfeld, 6.cd Nxd5, 7.O-O |
14. T Thorhallsson vs D Olafsson |
| ½-½ | 27 | 1987 | ISL-ch | A50 Queen's Pawn Game |
15. T Thorhallsson vs H Olafsson |
| 0-1 | 70 | 1987 | ISL-ch | B80 Sicilian, Scheveningen |
16. Petursson vs T Thorhallsson |
| 1-0 | 33 | 1987 | ISL-ch | B08 Pirc, Classical |
17. G Thorhallsson vs T Thorhallsson |
| 0-1 | 30 | 1987 | ISL-ch | C04 French, Tarrasch, Guimard Main line |
18. T Thorhallsson vs S Bjarnason |
| 1-0 | 41 | 1987 | ISL-ch | C15 French, Winawer |
19. T Thorhallsson vs O Kristjansson |
| ½-½ | 44 | 1987 | ISL-ch | E69 King's Indian, Fianchetto, Classical Main line |
20. Stefansson vs T Thorhallsson |
| 1-0 | 29 | 1987 | ISL-ch | B80 Sicilian, Scheveningen |
21. T Thorhallsson vs K Thorsteins |
| ½-½ | 19 | 1987 | ISL-ch | B40 Sicilian |
22. T Thorhallsson vs T Arnason |
| ½-½ | 11 | 1987 | ISL-ch | C17 French, Winawer, Advance |
23. D Hansson vs T Thorhallsson |
| 0-1 | 38 | 1987 | ISL-ch | C61 Ruy Lopez, Bird's Defense |
24. J Vidarsson vs T Thorhallsson |
| ½-½ | 24 | 1987 | ISL-ch | B80 Sicilian, Scheveningen |
25. A Karason vs T Thorhallsson |
| 1-0 | 34 | 1987 | ISL-ch | D35 Queen's Gambit Declined |