ecocodes
Volume B · Semi-open games‹ B26B28 ›
a1b2c3d4e5f6g7h8
Reference position · Black to move

B27 Sicilian Defense

Also filed here: Pterodactyl Defense, Modern Defense.

B27 holds 23 named lines from three openings, most of them (15) under Sicilian Defense. It leaves B20, a position of the same name, with 2.Nf3. Lines of 73 other codes continue from its position, the second-widest spread of the 80 Sicilian Defense codes. Material is no longer level at the end of four of its lines; the widest gap, one pawn in White’s favour, comes in Pterodactyl Defense: Sicilian, Pteranodon. With 23 named lines it is the third-largest code of the 80 Sicilian Defense codes.

Score sheet
#WhiteBlack
1e4c5
2Nf3

The move that completes B27

The reference line of B28 plays all of these moves and continues beyond them; B27 is the position reached at 2.Nf3.

  1. 2.Nf3 The knight leaves g1 for f3, opening a line for the rook on h1.

Lines filed under B27

All 23 share their first three plies, the whole reference line and then split eight ways at Black’s move 2.

NameAfter the shared startPliesAt the end
Sicilian Defense(the shared start itself)3
Sicilian Defense: Brussels Gambit2...f54
Sicilian Defense: Bücker Variation2...h64
Sicilian Defense: Hyperaccelerated Dragon2...g64
Sicilian Defense: Jalalabad Variation2...e54
Sicilian Defense: Katalimov Variation2...b64
Sicilian Defense: Mongoose Variation2...Qa54
Sicilian Defense: Polish Gambit2...b54
Sicilian Defense: Quinteros Variation2...Qc74
Sicilian Defense: Hyperaccelerated Dragon2...g6 3.d45
Sicilian Defense: Acton Extension2...g6 3.c4 Bh66
Sicilian Defense: Double-Dutch Gambit2...f5 3.exf5 Nh66White +1
Sicilian Defense: Frederico Variation2...g6 3.d4 f56
Sicilian Defense: Hyperaccelerated Pterodactyl2...g6 3.d4 Bg76
Modern Defense: Pterodactyl Variation2...g6 3.d4 Bg7 4.Nc3 Qa58
Pterodactyl Defense: Western, Pterodactyl2...g6 3.c3 Bg7 4.d4 Qa58
Pterodactyl Defense: Western, Rhamphorhynchus2...g6 3.d4 Bg7 4.dxc5 Qa5+8White +1, check
Pterodactyl Defense: Sicilian, Anhanguera2...g6 3.d4 Bg7 4.Nc3 Qa5 5.Be39
Pterodactyl Defense: Sicilian, Benoni Gambit2...g6 3.d4 Bg7 4.Nc3 Qa5 5.d59
Pterodactyl Defense: Sicilian, Rhamphorhynchus2...g6 3.d4 Bg7 4.dxc5 Qa5+ 5.Nc39White +1
Pterodactyl Defense: Sicilian, Unpin2...g6 3.d4 Bg7 4.Nc3 Qa5 5.Bd29
Pterodactyl Defense: Sicilian, Pteranodon2...g6 3.d4 Bg7 4.dxc5 Qa5+ 5.Nc3 Bxc3+ 6.bxc311White +1
Sicilian Defense: Hyperaccelerated Pterodactyl, Exchange Variation2...g6 3.d4 Bg7 4.dxc5 Qa5+ 5.Nc3 Bxc3+ 6.bxc3 Qxc3+12check

The road to B27

  1. 1.e4B00 King’s Pawn Game
  2. 1...c5B20 Sicilian Defense
  3. 2.Nf3B27

The position after 2.Nf3

White has brought out the knight on f3; Black has not yet moved a knight or bishop. Black is to move and has 22 legal moves.

WhiteBlackMaterial (pawn units)3939Minor pieces developed10Moves spent on pawns11Pawns on d4, e4, d5, e510Squares attacked in the other half62not castlednot castled

Codes that branch off from B27

The reference lines of five other codes leave B27 from the position after 2.Nf3, each with its own moves.

CodeMovesReference line
B282...a6Sicilian Defense: O’Kelly Variation
B292...Nf6Sicilian Defense: Nimzowitsch Variation
B302...Nc6Sicilian Defense: Old Sicilian
B402...e6Sicilian Defense: French Variation
B502...d6Sicilian Defense: Modern Variations

Closest boards in other codes

CodeLineDiffers on
A04Zukertort Openingfour squares: e2, e4, c5, c7
B00King’s Pawn Gamefour squares: g1, f3, c5, c7
B10Caro-Kann Defensefour squares: g1, f3, c5, c6
B21Sicilian Defense: McDonnell Attackfour squares: g1, f2, f3, f4
B22Sicilian Defense: Alapin Variationfour squares: g1, c2, c3, f3
B23Sicilian Defense: Closedfour squares: b1, g1, c3, f3
B32Sicilian Defense: Openfour squares: d2, d4, c6, b8

Where lines continue from here

Besides the codes above, they belong to B22, B31, B32, B33, B34, B35, B36, B37, B38, B39, B41, B42, B43, B44, B45, B46, B47, B48, B49, B51, B52, B53, B54, B55, B56, B57, B58, B59, B60, B61, B62, B63, B64, B65, B66, B67, B68, B69, B70, B71, B72, B73, B74, B75, B76, B77, B78, B79, B80, B81, B82, B83, B84, B85, B86, B87, B88, B89, B90, B91, B92, B93, B94, B95, B96, B97, B98, B99.

Volume B

  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

Other move orders

  • Modern Defense: Pterodactyl Variation is also reached inside B06 Pterodactyl Defense: Sicilian, Quetzalcoatlus, whose order is 1.e4 g6 2.d4 Bg7 3.Nc3 c5 4.Nf3 Qa5.
  • Sicilian Defense: Hyperaccelerated Pterodactyl is also reached inside B06 Pterodactyl Defense: Western, Anhanguera, whose order is 1.e4 g6 2.d4 Bg7 3.Nf3 c5.

Open this line in the finderAll Sicilian Defense codes