| Game |
| Result | Moves |
Year |
Event/Locale | Opening |
| 26. Balashov vs J L Arnason |
| ½-½ | 20 |
1980 |
Lone Pine | D18 Queen's Gambit Declined Slav, Dutch |
| 27. J L Arnason vs E Torre |
| ½-½ | 47 |
1980 |
Sochi | C91 Ruy Lopez, Closed |
| 28. Ribli vs J L Arnason |
| 1-0 | 42 |
1980 |
Malta ol (Men) | A07 King's Indian Attack |
| 29. J L Arnason vs Suetin |
| 0-1 | 39 |
1980 |
Sochi | B42 Sicilian, Kan |
| 30. J L Arnason vs R Mascarinas |
| ½-½ | 23 |
1980 |
Malta ol (Men) | B83 Sicilian |
| 31. J L Arnason vs Vasiukov |
| ½-½ | 72 |
1980 |
Reykjavik | B16 Caro-Kann, Bronstein-Larsen Variation |
| 32. J L Arnason vs Petursson |
| 0-1 | 59 |
1980 |
Reykjavik | C82 Ruy Lopez, Open |
| 33. L Shamkovich vs J L Arnason |
| 0-1 | 22 |
1980 |
Lone Pine | B43 Sicilian, Kan, 5.Nc3 |
| 34. J L Arnason vs R Byrne |
| 0-1 | 54 |
1980 |
Reykjavik | B92 Sicilian, Najdorf, Opocensky Variation |
| 35. J L Arnason vs Jansa |
| 1-0 | 37 |
1980 |
Sochi | B83 Sicilian |
| 36. Dzindzichashvili vs J L Arnason |
| ½-½ | 11 |
1980 |
03, Manhattan CC | D14 Queen's Gambit Declined Slav, Exchange Variation |
| 37. J L Arnason vs Christiansen |
 | 1-0 | 50 |
1980 |
Lone Pine | B16 Caro-Kann, Bronstein-Larsen Variation |
| 38. J L Arnason vs Panno |
| 0-1 | 35 |
1980 |
Lone Pine | B42 Sicilian, Kan |
| 39. J L Arnason vs Balashov |
| 0-1 | 30 |
1980 |
Sochi | C91 Ruy Lopez, Closed |
| 40. Larsen vs J L Arnason |
 | 1-0 | 46 |
1980 |
Lone Pine | A20 English |
| 41. J L Arnason vs R Henley |
| ½-½ | 31 |
1980 |
Lone Pine | C34 King's Gambit Accepted |
| 42. Vaganian vs J L Arnason |
| 1-0 | 28 |
1980 |
Sochi | D19 Queen's Gambit Declined Slav, Dutch |
| 43. Ivkov vs J L Arnason |
| ½-½ | 56 |
1980 |
Sochi | A70 Benoni, Classical with 7.Nf3 |
| 44. Van der Wiel vs J L Arnason |
 | 1-0 | 37 |
1980 |
Sochi | B83 Sicilian |
| 45. Qi Jingxuan vs J L Arnason |
| ½-½ | 44 |
1980 |
Malta ol (Men) | A22 English |
| 46. J L Arnason vs Quinteros |
| ½-½ | 45 |
1980 |
Lone Pine | B92 Sicilian, Najdorf, Opocensky Variation |
| 47. J L Arnason vs Alburt |
| 0-1 | 45 |
1980 |
Lone Pine | B03 Alekhine's Defense |
| 48. J L Arnason vs Balashov |
| ½-½ | 23 |
1980 |
MLT | C36 King's Gambit Accepted, Abbazia Defense |
| 49. Fedorowicz vs J L Arnason |
| ½-½ | 24 |
1980 |
New York MCC | B32 Sicilian |
| 50. Adianto vs J L Arnason |
| 1-0 | 36 |
1980 |
Wch U20 | B83 Sicilian |