| Game |
| Result | Moves |
Year | Event/Locale | Opening |
| 1. A Ornstein vs P G Henry |
| ½-½ | 26 | 1969 | Niemeyer Juniors Preliminary | E44 Nimzo-Indian, Fischer Variation, 5.Ne2 |
| 2. A Beliavsky vs A Ornstein |
| 1-0 | 27 | 1969 | Niemeyer Juniors Preliminary | E61 King's Indian |
| 3. A Ornstein vs U Schulze |
| 1-0 | 36 | 1969 | Niemeyer Juniors Preliminary | E92 King's Indian |
| 4. A Ornstein vs G Ligterink |
| 1-0 | 31 | 1969 | Niemeyer Juniors Preliminary | E43 Nimzo-Indian, Fischer Variation |
| 5. R Eales vs A Ornstein |
| ½-½ | 21 | 1969 | Niemeyer Juniors Preliminary | E63 King's Indian, Fianchetto, Panno Variation |
| 6. A Urzica vs A Ornstein |
| 1-0 | 45 | 1969 | Niemeyer Juniors Preliminary | B30 Sicilian |
| 7. A Ornstein vs M Schauwecker |
| ½-½ | 41 | 1969 | Niemeyer Juniors Preliminary | E45 Nimzo-Indian, 4.e3, Bronstein (Byrne) Variation |
| 8. D L Henry vs A Ornstein |
| 0-1 | 41 | 1970 | EU-ch U20 Final B | E62 King's Indian, Fianchetto |
| 9. A Ornstein vs Westerinen |
| 0-1 | 35 | 1971 | Stockholm op | C73 Ruy Lopez, Modern Steinitz Defense |
| 10. D Uddenfeldt vs A Ornstein |
| ½-½ | 61 | 1972 | SWE-ch | E80 King's Indian, Samisch Variation |
| 11. A Ornstein vs A Lombard |
 | 0-1 | 20 | 1972 | WchT U26 19th fin-B | B80 Sicilian, Scheveningen |
| 12. A Ornstein vs G Sigurjonsson |
| 0-1 | 67 | 1972 | WchT U26 19th fin-B | B06 Robatsch |
| 13. S Cvetkovic vs A Ornstein |
| 1-0 | 47 | 1972 | WchT U26 19th fin-B | E42 Nimzo-Indian, 4.e3 c5, 5.Ne2 (Rubinstein) |
| 14. A Ornstein vs G Brostrom |
| 1-0 | 54 | 1972 | SWE-ch | B52 Sicilian, Canal-Sokolsky (Rossolimo) Attack |
| 15. A Ornstein vs T Stefansson |
 | 1-0 | 25 | 1972 | EU-ch U20 fin-C | E66 King's Indian, Fianchetto, Yugoslav Panno |
| 16. A Ornstein vs H Ek |
| 1-0 | 41 | 1972 | SWE-ch | C07 French, Tarrasch |
| 17. M Wahlbom vs A Ornstein |
| ½-½ | 60 | 1972 | SWE-ch | A39 English, Symmetrical, Main line with d4 |
| 18. J Eslon vs A Ornstein |
| 0-1 | 38 | 1972 | SWE-ch | B43 Sicilian, Kan, 5.Nc3 |
| 19. A Ornstein vs G Sperber |
| 1-0 | 26 | 1972 | SWE-ch | B57 Sicilian |
| 20. E Raaste vs A Ornstein |
| 0-1 | 29 | 1972 | WchT U26 19th fin-B | A01 Nimzovich-Larsen Attack |
| 21. A Ornstein vs O Kinnmark |
| 1-0 | 48 | 1972 | SWE-ch | A17 English |
| 22. S Heim vs A Ornstein |
| 0-1 | 27 | 1972 | WchT U26 19th fin-B | C45 Scotch Game |
| 23. A J van Dop vs A Ornstein |
| ½-½ | 79 | 1972 | WchT U26 19th fin-B | B42 Sicilian, Kan |
| 24. A Ornstein vs L Liljedahl |
| ½-½ | 42 | 1972 | SWE-ch | B05 Alekhine's Defense, Modern |
| 25. A Olsson vs A Ornstein |
| ½-½ | 73 | 1972 | SWE-ch | C45 Scotch Game |
Kibitzing
