| Game |
| Result | Moves |
Year |
Event/Locale | Opening |
| 1. Leonhardt vs F Brown |
 | 1-0 | 82 |
1903 |
Hilversum | C62 Ruy Lopez, Old Steinitz Defense |
| 2. Leonhardt vs A Speyer |
| ½-½ | 71 |
1903 |
Hilversum | C88 Ruy Lopez |
| 3. Leonhardt vs Loman |
 | 1-0 | 27 |
1903 |
Hilversum | C78 Ruy Lopez |
| 4. Leonhardt vs J Esser |
 | 1-0 | 16 |
1905 |
**Rd--()-, Schevenin | C67 Ruy Lopez |
| 5. Leonhardt vs Marshall |
| 0-1 | 21 |
1905 |
Scheveningen | C70 Ruy Lopez |
| 6. Leonhardt vs Teichmann |
| 0-1 | 31 |
1905 |
Ostende | C67 Ruy Lopez |
| 7. Leonhardt vs Gunston / Shoosmith |
| 1-0 | 36 |
1905 |
ENG-USA cable m | C84 Ruy Lopez, Closed |
| 8. Leonhardt vs H Wolf |
| 0-1 | 26 |
1905 |
Ostend | C79 Ruy Lopez, Steinitz Defense Deferred |
| 9. Leonhardt vs Salwe |
| 0-1 | 61 |
1906 |
DSB-15.Kongress | C86 Ruy Lopez, Worrall Attack |
| 10. Leonhardt vs E Cohn |
| 1-0 | 28 |
1906 |
Ostend | C67 Ruy Lopez |
| 11. Leonhardt vs Schlechter |
| ½-½ | 46 |
1906 |
DSB-15.Kongress | C72 Ruy Lopez, Modern Steinitz Defense, 5.O-O |
| 12. Leonhardt vs Dus Chotimirsky |
| 1-0 | 36 |
1907 |
Carlsbad it, CZE | C63 Ruy Lopez, Schliemann Defense |
| 13. Leonhardt vs Marshall |
| ½-½ | 51 |
1907 |
Carlsbad it, CZE | C62 Ruy Lopez, Old Steinitz Defense |
| 14. Leonhardt vs Spielmann |
| 0-1 | 28 |
1908 |
Prague | C70 Ruy Lopez |
| 15. Leonhardt vs H Suechting |
| ½-½ | 45 |
1908 |
Prague | C66 Ruy Lopez |
| 16. Leonhardt vs Teichmann |
| ½-½ | 38 |
1908 |
Vienna | C77 Ruy Lopez |
| 17. Leonhardt vs A Rabinovich |
 | 1-0 | 40 |
1908 |
Prague | C65 Ruy Lopez, Berlin Defense |
| 18. Leonhardt vs Salwe |
| ½-½ | 29 |
1908 |
Vienna | C77 Ruy Lopez |
| 19. Leonhardt vs Marshall |
| ½-½ | 42 |
1908 |
Praha | C80 Ruy Lopez, Open |
| 20. Leonhardt vs Duras |
| ½-½ | 86 |
1909 |
Gothenburg-A | C84 Ruy Lopez, Closed |
| 21. Leonhardt vs Kohnlein |
| 0-1 | 60 |
1910 |
DSB-17.Kongress | C80 Ruy Lopez, Open |
| 22. Leonhardt vs Yates |
| 1-0 | 23 |
1910 |
DSB-17.Kongress | C78 Ruy Lopez |
| 23. Leonhardt vs Salwe |
| 1-0 | 66 |
1910 |
DSB-17.Kongress | C66 Ruy Lopez |
| 24. Leonhardt vs Rubinstein |
| 0-1 | 43 |
1911 |
Karlsbad | C77 Ruy Lopez |
| 25. Leonhardt vs Rubinstein |
| 0-1 | 54 |
1911 |
San Sebastian | C98 Ruy Lopez, Closed, Chigorin |