| Game |
| Result | Moves |
Year | Event/Locale | Opening |
| 26. J Halfdanarson vs M Acosta |
| 1-0 | 51 | 1969 | World Student Team Championship Final-B | A11 English, Caro-Kann Defensive System |
| 27. F Nordstrom vs J Halfdanarson |
| 0-1 | 60 | 1969 | World Student Team Championship Final-B | A56 Benoni Defense |
| 28. J Halfdanarson vs A Marat |
| 0-1 | 26 | 1969 | World Student Team Championship Final-B | A11 English, Caro-Kann Defensive System |
| 29. R Hernandez Onna vs J Halfdanarson |
| 1-0 | 35 | 1969 | World Student Team Championship Final-B | A73 Benoni, Classical, 9.O-O |
| 30. J Halfdanarson vs J Aijala |
| 1-0 | 33 | 1969 | World Student Team Championship Final-B | A59 Benko Gambit |
| 31. I Farago vs J Halfdanarson |
| 1-0 | 28 | 1969 | World Student Team Championship Final-B | A57 Benko Gambit |
| 32. A Soltis vs J Halfdanarson |
| 1-0 | 34 | 1970 | 17th StudWTCh final | C85 Ruy Lopez, Exchange Variation Doubly Deferred (DERLD) |
| 33. T Oral vs J Halfdanarson |
| 1-0 | 48 | 2000 | ISL-chT 0001 | C04 French, Tarrasch, Guimard Main line |
| 34. Hjartarson vs J Halfdanarson |
 | 1-0 | 47 | 2017 | ISL-chT Div 1 2017/18 | C18 French, Winawer |
Kibitzing
