| Game |
| Result | Moves |
Year |
Event/Locale | Opening |
| 1. A Neumann vs Leonhardt |
 | 0-1 | 95 |
1903 |
Hilversum | C79 Ruy Lopez, Steinitz Defense Deferred |
| 2. J Vijzelaar vs Leonhardt |
| 0-1 | 56 |
1903 |
Hilversum | C84 Ruy Lopez, Closed |
| 3. M Lange vs Leonhardt |
| 0-1 | 36 |
1903 |
Hilversum | C87 Ruy Lopez |
| 4. J F Heemskerk vs Leonhardt |
| 1-0 | 30 |
1903 |
Hilversum | C68 Ruy Lopez, Exchange |
| 5. G Schories vs Leonhardt |
| 1-0 | 35 |
1904 |
London m4 | C87 Ruy Lopez |
| 6. G Schories vs Leonhardt |
| 0-1 | 36 |
1904 |
London m4 | C67 Ruy Lopez |
| 7. H Wolf vs Leonhardt |
| ½-½ | 60 |
1905 |
Barmen Masters A, GER | C84 Ruy Lopez, Closed |
| 8. G Marco vs Leonhardt |
| ½-½ | 36 |
1905 |
Ostend | C67 Ruy Lopez |
| 9. W John vs Leonhardt |
| 0-1 | 52 |
1905 |
Barmen Masters A, GER | C67 Ruy Lopez |
| 10. H Wolf vs Leonhardt |
| 0-1 | 43 |
1905 |
Ostend | C67 Ruy Lopez |
| 11. H Suechting vs Leonhardt |
| ½-½ | 32 |
1905 |
Barmen Masters A, GER | C67 Ruy Lopez |
| 12. G Schories vs Leonhardt |
| ½-½ | 56 |
1905 |
Scheveningen | C67 Ruy Lopez |
| 13. Schlechter vs Leonhardt |
 | 1-0 | 40 |
1905 |
Ostend | C72 Ruy Lopez, Modern Steinitz Defense, 5.O-O |
| 14. Teichmann vs Leonhardt |
| 0-1 | 34 |
1905 |
Ostend | C67 Ruy Lopez |
| 15. Teichmann vs Leonhardt |
| 1-0 | 24 |
1905 |
Berlin | C67 Ruy Lopez |
| 16. Duras vs Leonhardt |
| 1-0 | 39 |
1905 |
Scheveningen | C65 Ruy Lopez, Berlin Defense |
| 17. H Wolf vs Leonhardt |
| ½-½ | 44 |
1906 |
Nuremberg | C71 Ruy Lopez |
| 18. Duras vs Leonhardt |
| 1-0 | 23 |
1906 |
DSB-15.Kongress | C65 Ruy Lopez, Berlin Defense |
| 19. P F Johner vs Leonhardt |
 | 0-1 | 29 |
1907 |
Carlsbad it, CZE | C77 Ruy Lopez |
| 20. Olland vs Leonhardt |
| 0-1 | 43 |
1907 |
Carlsbad it, CZE | C67 Ruy Lopez |
| 21. Prokes vs Leonhardt |
| 0-1 | 30 |
1908 |
Prague | C88 Ruy Lopez |
| 22. F Treybal vs Leonhardt |
| 0-1 | 26 |
1908 |
Prague | C67 Ruy Lopez |
| 23. Spielmann vs Leonhardt |
| ½-½ | 40 |
1908 |
Vienna | C78 Ruy Lopez |
| 24. Von Bardeleben vs Leonhardt |
 | 0-1 | 54 |
1908 |
Vienna | C63 Ruy Lopez, Schliemann Defense |
| 25. Duras vs Leonhardt |
| 1-0 | 28 |
1908 |
Prague | C77 Ruy Lopez |