| Game |
| Result | Moves |
Year | Event/Locale | Opening |
| 1. C Kockelkorn vs C Leffmann |
| 0-1 | 36 | 1871 | Krefeld Rheinisches Hauptturnier | C50 Giuoco Piano |
| 2. C Leffmann vs E Hammacher |
| 1-0 | 27 | 1871 | Krefeld Rheinisches Hauptturnier | C00 French Defense |
| 3. R Lichtenscheidt vs C Leffmann |
| 0-1 | 22 | 1871 | Krefeld Rheinisches Hauptturnier | C74 Ruy Lopez, Modern Steinitz Defense |
| 4. C Leffmann vs F Hipp |
| 1-0 | 51 | 1871 | Krefeld Rheinisches Hauptturnier | C38 King's Gambit Accepted |
| 5. de Rives vs C Leffmann |
| 0-1 | 22 | 1873 | Brussels | C53 Giuoco Piano |
| 6. W Paulsen vs C Leffmann |
| ½-½ | 34 | 1877 | 3rd MSB Congress, Leipzig | B46 Sicilian, Taimanov Variation |
| 7. E Schallopp vs C Leffmann |
 | 0-1 | 35 | 1877 | 3rd MSB Congress, Leipzig | C80 Ruy Lopez, Open |
| 8. C Leffmann vs Zukertort |
 | 0-1 | 59 | 1877 | 3rd MSB Congress, Leipzig | C50 Giuoco Piano |
| 9. E Flechsig vs C Leffmann |
| 0-1 | 47 | 1877 | 3rd MSB Congress, Leipzig | C48 Four Knights |
| 10. J Metger vs C Leffmann |
| ½-½ | 24 | 1877 | 3rd MSB Congress, Leipzig | C48 Four Knights |
| 11. C Leffmann vs Winawer |
| 0-1 | 31 | 1877 | 3rd MSB Congress, Leipzig | C46 Three Knights |
| 12. Paulsen vs C Leffmann |
| 1-0 | 18 | 1877 | 3rd MSB Congress, Leipzig | A84 Dutch |
| 13. C Leffmann vs Englisch |
| 0-1 | 41 | 1877 | 3rd MSB Congress, Leipzig | C80 Ruy Lopez, Open |
| 14. C Leffmann vs Anderssen |
| 0-1 | 32 | 1877 | 3rd MSB Congress, Leipzig | C67 Ruy Lopez |
| 15. A W Franke vs C Leffmann |
| 0-1 | 20 | 1877 | 3rd MSB Congress, Leipzig | C02 French, Advance |
| 16. C Leffmann vs C Goering |
| 1-0 | 36 | 1877 | 3rd MSB Congress, Leipzig | C50 Giuoco Piano |
| 17. C Leffmann vs W Paulsen |
| 0-1 | 49 | 1883 | 3rd DSB Congress, Nuremberg | B43 Sicilian, Kan, 5.Nc3 |
| 18. C Leffmann vs M Weiss |
| ½-½ | 49 | 1883 | 3rd DSB Congress, Nuremberg | C70 Ruy Lopez |
| 19. A Fritz vs C Leffmann |
| ½-½ | 23 | 1883 | 3rd DSB Congress, Nuremberg | C49 Four Knights |
| 20. C Leffmann vs von Bardeleben |
| 0-1 | 66 | 1883 | 3rd DSB Congress, Nuremberg | B46 Sicilian, Taimanov Variation |
| 21. C Leffmann vs Gunsberg |
| 0-1 | 39 | 1883 | 3rd DSB Congress, Nuremberg | C83 Ruy Lopez, Open |
| 22. J Berger vs C Leffmann |
| 1-0 | 56 | 1883 | 3rd DSB Congress, Nuremberg | C77 Ruy Lopez |
| 23. V Hruby vs C Leffmann |
| 1-0 | 25 | 1883 | 3rd DSB Congress, Nuremberg | A13 English |
| 24. M Lange vs C Leffmann |
| 1-0 | 27 | 1883 | 3rd DSB Congress, Nuremberg | C50 Giuoco Piano |
| 25. Blackburne vs C Leffmann |
| ½-½ | 81 | 1883 | 3rd DSB Congress, Nuremberg | C53 Giuoco Piano |
Kibitzing
