| Game |
| Result | Moves |
Year |
Event/Locale | Opening |
| 26. Plachetka vs J Augustin |
| 1-0 | 21 |
1964 |
Harrachov 6465 | A14 English |
| 27. K Eretova vs Plachetka |
| 0-1 | 41 |
1964 |
Harrachov 6465 | B16 Caro-Kann, Bronstein-Larsen Variation |
| 28. P Voboril vs Plachetka |
| 0-1 | 59 |
1964 |
Harrachov 6465 | B73 Sicilian, Dragon, Classical |
| 29. B Sorensen vs Plachetka |
| 0-1 | 40 |
1965 |
WchT U26 12th fin-A | D34 Queen's Gambit Declined, Tarrasch |
| 30. Plachetka vs J Bellin |
| 1-0 | 42 |
1965 |
Harrachov U26 | B41 Sicilian, Kan |
| 31. Poppy J Aarons vs Plachetka |
| 0-1 | 19 |
1965 |
Klasterec nad Orlici U18 6566 | B66 Sicilian, Richter-Rauzer Attack, 7...a6 |
| 32. P Ferenc vs Plachetka |
| 0-1 | 42 |
1965 |
Harrachov U26 | B34 Sicilian, Accelerated Fianchetto |
| 33. D Trejbal vs Plachetka |
| 0-1 | 36 |
1965 |
Klasterec nad Orlici U18 6566 | D32 Queen's Gambit Declined, Tarrasch |
| 34. E Nagy vs Plachetka |
| 1-0 | 37 |
1965 |
WchT U26 12th fin-A | A07 King's Indian Attack |
| 35. M Janata vs Plachetka |
| ½-½ | 25 |
1965 |
Harrachov U26 | B01 Scandinavian |
| 36. Vladimir Kosina vs Plachetka |
| 0-1 | 45 |
1965 |
Klasterec nad Orlici U18 6566 | A15 English |
| 37. Plachetka vs M Seifert |
| 1-0 | 39 |
1965 |
Harrachov U26 | E91 King's Indian |
| 38. Plachetka vs A Kubicek |
| ½-½ | 35 |
1965 |
Klasterec nad Orlici U18 6566 | D91 Grunfeld, 5.Bg5 |
| 39. Plachetka vs V Tichy |
| ½-½ | 28 |
1965 |
Harrachov U26 | C42 Petrov Defense |
| 40. Plachetka vs J Franzen |
| 0-1 | 27 |
1965 |
Klasterec nad Orlici U18 6566 | C97 Ruy Lopez, Closed, Chigorin |
| 41. Plachetka vs J Kasanen |
| 1-0 | 27 |
1965 |
WchT U26 12th prel | D50 Queen's Gambit Declined |
| 42. Pribyl vs Plachetka |
| ½-½ | 42 |
1965 |
Klasterec nad Orlici U18 6566 | D32 Queen's Gambit Declined, Tarrasch |
| 43. E Nowak vs Plachetka |
| ½-½ | 52 |
1965 |
Harrachov U26 | B63 Sicilian, Richter-Rauzer Attack |
| 44. Ivo Ryc vs Plachetka |
| ½-½ | 17 |
1965 |
Klasterec nad Orlici U18 6566 | C41 Philidor Defense |
| 45. M Wahlbom vs Plachetka |
| 0-1 | 93 |
1965 |
WchT U26 12th prel | E62 King's Indian, Fianchetto |
| 46. J Petras vs Plachetka |
| 0-1 | 18 |
1965 |
Harrachov U26 | E63 King's Indian, Fianchetto, Panno Variation |
| 47. Plachetka vs I Novak |
| 0-1 | 31 |
1965 |
Klasterec nad Orlici U18 6566 | C64 Ruy Lopez, Classical |
| 48. Plachetka vs Smejkal |
| ½-½ | 24 |
1965 |
Harrachov U26 | D91 Grunfeld, 5.Bg5 |
| 49. Plachetka vs M Janata |
| ½-½ | 23 |
1965 |
Klasterec nad Orlici U18 6566 | E14 Queen's Indian |
| 50. Plachetka vs D Trejbal |
| ½-½ | 39 |
1966 |
Harrachov U26 | E14 Queen's Indian |