| Game |
| Result | Moves |
Year | Event/Locale | Opening |
| 26. G MacDonnell vs Steinitz |
  | 1-0 | 29 | 1862 | 5th BCA Congress, London | C44 King's Pawn Game |
| 27. G MacDonnell vs Blackburne |
| 1-0 | 50 | 1862 | 5th BCA Congress, London | C54 Giuoco Piano |
| 28. J Robey vs G MacDonnell |
| 0-1 | 46 | 1862 | 5th BCA Congress, London | C41 Philidor Defense |
| 29. J Owen vs G MacDonnell |
| 0-1 | 52 | 1862 | 5th BCA Congress, London | A35 English, Symmetrical |
| 30. G MacDonnell vs Mackenzie |
| 1-0 | 47 | 1862 | MacDonnell - Mackenzie 1862/63 | C50 Giuoco Piano |
| 31. G MacDonnell vs Mackenzie |
| 1-0 | 49 | 1862 | MacDonnell - Mackenzie 1862/63 | C50 Giuoco Piano |
| 32. Mackenzie vs G MacDonnell |
| 1-0 | 47 | 1862 | MacDonnell - Mackenzie 1862/63 | C41 Philidor Defense |
| 33. G MacDonnell vs Mackenzie |
| 0-1 | 28 | 1862 | MacDonnell - Mackenzie 1862/63 | C42 Petrov Defense |
| 34. Mackenzie vs G MacDonnell |
| 0-1 | 64 | 1862 | MacDonnell - Mackenzie 1862/63 | C41 Philidor Defense |
| 35. Mackenzie vs G MacDonnell |
| 1-0 | 47 | 1862 | MacDonnell - Mackenzie 1862/63 | C41 Philidor Defense |
| 36. G MacDonnell vs Mackenzie |
| 0-1 | 27 | 1862 | MacDonnell - Mackenzie 1862/63 | C01 French, Exchange |
| 37. Mackenzie vs G MacDonnell |
| 1-0 | 48 | 1862 | MacDonnell - Mackenzie 1862/63 | A00 Uncommon Opening |
| 38. G MacDonnell vs C De Vere |
| 1-0 | 21 | 1863 | Odds game | 000 Chess variants |
| 39. G MacDonnell vs Mackenzie |
| ½-½ | 37 | 1863 | MacDonnell - Mackenzie 1862/63 | A10 English |
| 40. Mackenzie vs G MacDonnell |
| 1-0 | 36 | 1863 | MacDonnell - Mackenzie 1862/63 | A00 Uncommon Opening |
| 41. G MacDonnell vs P Duffy |
| 1-0 | 49 | 1865 | Casual game | C51 Evans Gambit |
| 42. E Cordner vs G MacDonnell |
| 0-1 | 41 | 1865 | Dublin | C53 Giuoco Piano |
| 43. G MacDonnell vs E Cronhelm |
| 1-0 | 44 | 1865 | Dublin | C01 French, Exchange |
| 44. W Bolt vs G MacDonnell |
| 0-1 | 64 | 1865 | Dublin | C42 Petrov Defense |
| 45. Steinitz vs G MacDonnell |
| 1-0 | 50 | 1865 | Dublin | C41 Philidor Defense |
| 46. G MacDonnell vs Steinitz |
| ½-½ | 29 | 1865 | Dublin | C67 Ruy Lopez |
| 47. J I Minchin vs G MacDonnell |
| 0-1 | 46 | 1866 | 6th BCA Congress, 1st Challenge Cup, London | A20 English |
| 48. G MacDonnell vs J I Minchin |
| 1-0 | 29 | 1866 | 6th BCA Congress, 1st Challenge Cup, London | C84 Ruy Lopez, Closed |
| 49. G MacDonnell vs J I Minchin |
| ½-½ | 53 | 1866 | 6th BCA Congress, 1st Challenge Cup, London | C67 Ruy Lopez |
| 50. G MacDonnell vs C De Vere |
| 0-1 | 19 | 1866 | 6th BCA Congress, 1st Challenge Cup, London | C53 Giuoco Piano |
Kibitzing
