ecocodes
Volume E · Indian defenses‹ E42E44 ›
a1b2c3d4e5f6g7h8
Reference position · White to move

E43 Nimzo-Indian Defense: St. Petersburg Variation

E43 holds 12 named lines, all under the name Nimzo-Indian Defense. It leaves E40 (Nimzo-Indian Defense: Rubinstein System) with 4...b6. With 12 named lines it is the largest code of the 40 Nimzo-Indian Defense codes. That final move, by the b-pawn, covers a5 and c5 and opens a line for the bishop on c8.

Score sheet
#WhiteBlack
1d4Nf6
2c4e6
3Nc3Bb4
4e3b6

Lines filed under E43

All 12 share the start 1.d4 Nf6 2.c4 e6 3.Nc3 Bb4 and then split two ways at White’s move 4.

NameAfter the shared startPliesAt the end
Nimzo-Indian Defense: St. Petersburg Variation4.e3 b68
Nimzo-Indian Defense: St. Petersburg Variation4.e3 b6 5.Bd3 Bb7 6.Nf311
Nimzo-Indian Defense: St. Petersburg Variation4.Nf3 b6 5.e3 Ne4 6.Qc211
Nimzo-Indian Defense: St. Petersburg Variation4.e3 b6 5.Bd3 Bb7 6.Nf3 O-O12Black castled
Nimzo-Indian Defense: St. Petersburg Variation, with Ne44.e3 b6 5.Bd3 Bb7 6.Nf3 Ne412
Nimzo-Indian Defense: St. Petersburg Variation4.e3 b6 5.Bd3 Bb7 6.Nf3 O-O 7.O-O13both castled
Nimzo-Indian Defense: St. Petersburg Variation4.e3 b6 5.Bd3 Bb7 6.Nf3 O-O 7.O-O c514both castled
Nimzo-Indian Defense: St. Petersburg Variation4.e3 Ne4 5.Qc2 f5 6.Nf3 b6 7.Bd3 Bb714
Nimzo-Indian Defense: St. Petersburg Variation4.Nf3 Bxc3+ 5.bxc3 b6 6.e3 Bb7 7.Bd3 O-O 8.O-O15both castled
Nimzo-Indian Defense: St. Petersburg Variation4.e3 O-O 5.Bd3 c5 6.Nf3 b6 7.O-O Bb7 8.Na4 Qe716both castled
Nimzo-Indian Defense: St. Petersburg Variation4.Nf3 b6 5.e3 Ne4 6.Qc2 Bb7 7.Bd3 Bxc3+ 8.bxc3 f5 9.O-O17White castled
Nimzo-Indian Defense: St. Petersburg Variation4.e3 b6 5.Bd3 Bb7 6.Nf3 O-O 7.O-O c5 8.Na4 cxd4 9.a3 Be718Black +1, both castled

The road to E43

  1. 1.d4 … 3.Nc3three earlier stops: A40, A45, A50
  2. 3...Bb4E20 Nimzo-Indian Defense
  3. 4.e3E40 Rubinstein System
  4. 4...b6E43

The position after 4...b6

White has brought out the knight on c3; Black the knight on f6 and bishop on b4. White is to move and has 30 legal moves.

WhiteBlackMaterial (pawn units)3939Minor pieces developed12Moves spent on pawns32Pawns on d4, e4, d5, e510Squares attacked in the other half54not castlednot castled

Codes that branch off from E43

The reference lines of one other code leave E43 from the position after 4...b6, each with its own moves.

CodeMovesReference line
E445.Ne2Nimzo-Indian Defense: St. Petersburg Variation

Closest boards in other codes

CodeLineDiffers on
E20Nimzo-Indian Defensefour squares: e2, e3, b6, b7
E41Nimzo-Indian Defense: Rubinstein Systemfour squares: c5, b6, b7, c7
E45Nimzo-Indian Defense: St. Petersburg Variation, Fischer Variationfour squares: g1, e2, a6, c8
E14Queen’s Indian Defense: Spassky Systemsix squares: b1, g1, c3, f3, b4, f8
E21Nimzo-Indian Defense: Three Knights Variationsix squares: g1, e2, e3, f3, b6, b7
E22Nimzo-Indian Defense: Spielmann Variationsix squares: d1, e2, b3, e3, b6, b7
E24Nimzo-Indian Defense: Sämisch Variationsix squares: a2, e2, a3, e3, b6, b7

Where lines continue from here

Five named lines filed under other codes pass through the position after 4...b6. Besides the codes above, they belong to E45, E52.

Volume E

  1. 00
  2. 01
  3. 02
  4. 03
  5. 04
  6. 05
  7. 06
  8. 07
  9. 08
  10. 09
  11. 10
  12. 11
  13. 12
  14. 13
  15. 14
  16. 15
  17. 16
  18. 17
  19. 18
  20. 19
  21. 20
  22. 21
  23. 22
  24. 23
  25. 24
  26. 25
  27. 26
  28. 27
  29. 28
  30. 29
  31. 30
  32. 31
  33. 32
  34. 33
  35. 34
  36. 35
  37. 36
  38. 37
  39. 38
  40. 39
  41. 40
  42. 41
  43. 42
  44. 43
  45. 44
  46. 45
  47. 46
  48. 47
  49. 48
  50. 49
  51. 50
  52. 51
  53. 52
  54. 53
  55. 54
  56. 55
  57. 56
  58. 57
  59. 58
  60. 59
  61. 60
  62. 61
  63. 62
  64. 63
  65. 64
  66. 65
  67. 66
  68. 67
  69. 68
  70. 69
  71. 70
  72. 71
  73. 72
  74. 73
  75. 74
  76. 75
  77. 76
  78. 77
  79. 78
  80. 79
  81. 80
  82. 81
  83. 82
  84. 83
  85. 84
  86. 85
  87. 86
  88. 87
  89. 88
  90. 89
  91. 90
  92. 91
  93. 92
  94. 93
  95. 94
  96. 95
  97. 96
  98. 97
  99. 98
  100. 99

Open this line in the finderAll Nimzo-Indian Defense codes