| Game |
| Result | Moves |
Year | Event/Locale | Opening |
| 26. J Arnason vs Larsen |
 | 0-1 | 27 | 1978 | Reykjavik | C34 King's Gambit Accepted |
| 27. Hort vs J Arnason |
| 1-0 | 30 | 1978 | Reykjavik | A28 English |
| 28. J Arnason vs L Ogaard |
| ½-½ | 51 | 1978 | Reykjavik | B46 Sicilian, Taimanov Variation |
| 29. Browne vs J Arnason |
| 1-0 | 42 | 1978 | Reykjavik | A32 English, Symmetrical Variation |
| 30. J Arnason vs G Sigurjonsson |
| ½-½ | 16 | 1978 | Reykjavik | B83 Sicilian |
| 31. J Liang vs J Arnason |
| 1-0 | 45 | 1978 | Buenos Aires Olympiad | B33 Sicilian |
| 32. J Arnason vs A Bogda |
| ½-½ | 16 | 1978 | Buenos Aires Olympiad | B52 Sicilian, Canal-Sokolsky (Rossolimo) Attack |
| 33. G Bordonada vs J Arnason |
| 1-0 | 33 | 1978 | Buenos Aires Olympiad | B33 Sicilian |
| 34. J Arnason vs R Grinberg |
| 0-1 | 67 | 1978 | Buenos Aires Olympiad | B83 Sicilian |
| 35. J Arnason vs D Sellos |
| 1-0 | 39 | 1978 | Buenos Aires Olympiad | B47 Sicilian, Taimanov (Bastrikov) Variation |
| 36. A Zapata vs J Arnason |
| ½-½ | 63 | 1978 | Buenos Aires Olympiad | B45 Sicilian, Taimanov |
| 37. J Arnason vs N Padevsky |
| ½-½ | 57 | 1978 | Buenos Aires Olympiad | B84 Sicilian, Scheveningen |
| 38. J Arnason vs T Ghitescu |
| ½-½ | 20 | 1978 | Buenos Aires Olympiad | B51 Sicilian, Canal-Sokolsky (Rossolimo) Attack |
| 39. J Arnason vs S Garcia Martinez |
 | 0-1 | 52 | 1978 | Buenos Aires Olympiad | B32 Sicilian |
| 40. J Arnason vs P Ostberg |
| ½-½ | 33 | 1979 | Nordic-ch | C91 Ruy Lopez, Closed |
| 41. K Kaiszauri vs J Arnason |
| 0-1 | 60 | 1979 | Gladsaxe | B40 Sicilian |
| 42. J Kristiansen vs J Arnason |
| 1-0 | 41 | 1979 | Gladsaxe | B25 Sicilian, Closed |
| 43. J Arnason vs C Niklasson |
| ½-½ | 26 | 1979 | Gladsaxe | B47 Sicilian, Taimanov (Bastrikov) Variation |
| 44. T Wedberg vs J Arnason |
| 0-1 | 67 | 1979 | Gladsaxe | B42 Sicilian, Kan |
| 45. J Arnason vs L Schneider |
| ½-½ | 41 | 1979 | Gladsaxe | B62 Sicilian, Richter-Rauzer |
| 46. J Arnason vs C Hoi |
| 0-1 | 57 | 1979 | Gladsaxe | C11 French |
| 47. F Fuglsang vs J Arnason |
| ½-½ | 44 | 1979 | Gladsaxe | A34 English, Symmetrical |
| 48. J Arnason vs E Mortensen |
| 1-0 | 26 | 1979 | Gladsaxe | B84 Sicilian, Scheveningen |
| 49. J Arnason vs I Farago |
| ½-½ | 17 | 1979 | Rubinstein Memorial | C05 French, Tarrasch |
| 50. J Arnason vs Filip |
| ½-½ | 41 | 1979 | Rubinstein Memorial | C76 Ruy Lopez, Modern Steinitz Defense, Fianchetto Variation |
Kibitzing
