ecocodes
Volume B · Semi-open games‹ B19B21 ›
a1b2c3d4e5f6g7h8
Reference position · White to move

B20 Sicilian Defense

B20 holds 27 named lines, all under the name Sicilian Defense. It leaves B00 (King’s Pawn Game) with 1...c5. Lines of 80 other codes continue from its position, the widest spread of the 80 Sicilian Defense codes. At two plies, its reference line is the shortest of the 80 Sicilian Defense codes. Material is no longer level at the end of eight of its lines; the widest gap, two pawns in Black’s favour, comes in Sicilian Defense: Wing Gambit, Carlsbad Variation.

Score sheet
#WhiteBlack
1e4c5

The move that completes B20

The reference line of B21 plays all of these moves and continues beyond them; B20 is the position reached at 1...c5.

  1. 1...c5 The c-pawn advances two squares to c5, covering b4 and d4, opening a line for the queen on d8.

Lines filed under B20

All 27 share their first two plies, the whole reference line and then split 15 ways at White’s move 2.

NameAfter the shared startPliesAt the end
Sicilian Defense(the shared start itself)2
Sicilian Defense: Amazon Attack2.Qg43
Sicilian Defense: Bowdler Attack2.Bc43
Sicilian Defense: Brick Variation2.Nh33
Sicilian Defense: Czerniak Attack2.b33
Sicilian Defense: Grob Variation2.g43
Sicilian Defense: Keres Variation2.Ne23
Sicilian Defense: King David’s Opening2.Ke23
Sicilian Defense: Kronberger Variation2.Na33
Sicilian Defense: Lasker-Dunne Attack2.g33
Sicilian Defense: Mengarini Variation2.a33
Sicilian Defense: Myers Attack, with a42.a43
Sicilian Defense: Myers Attack, with h42.h43
Sicilian Defense: Staunton-Cochrane Variation2.c43
Sicilian Defense: Wing Gambit2.b43
Sicilian Defense: Czerniak Attack, Queen Fianchetto Variation2.b3 b64
Sicilian Defense: Euwe Attack, Prins Gambit2.b3 d5 3.Bb25
Sicilian Defense: Wing Gambit, Abrahams Variation2.b4 cxb4 3.Bb25Black +1
Sicilian Defense: Wing Gambit, Marshall Variation2.b4 cxb4 3.a35Black +1
Sicilian Defense: Wing Gambit, Santasiere Variation2.b4 cxb4 3.c45Black +1
Sicilian Defense: Wing Gambit, Carlsbad Variation2.b4 cxb4 3.a3 bxa36Black +2
Sicilian Defense: Big Clamp Formation2.d3 Nc6 3.c3 d6 4.f47
Sicilian Defense: Kronberger Variation, Nemeth Gambit2.Na3 Nc6 3.d4 cxd4 4.Bc47Black +1
Sicilian Defense: Gloria Variation2.c4 d6 3.Nc3 Nc6 4.g3 h58
Sicilian Defense: Wing Gambit, Marienbad Variation2.b4 cxb4 3.a3 d5 4.exd5 Qxd5 5.Bb29Black +1
Sicilian Defense: Wing Gambit, Nanu Gambit2.b4 cxb4 3.a3 d5 4.exd5 Qxd5 5.Nf3 e5 6.c4 Qe6 7.Bd313Black +1
Sicilian Defense: Wing Gambit, Romanian Defense2.b4 cxb4 3.a3 d5 4.exd5 Qxd5 5.Nf3 e5 6.Bb2 Nc6 7.c4 Qe614Black +1

The road to B20

  1. 1.e4B00 King’s Pawn Game
  2. 1...c5B20

The position after 1...c5

White is to move and has 30 legal moves.

WhiteBlackMaterial (pawn units)3939Minor pieces developed00Moves spent on pawns11Pawns on d4, e4, d5, e510Squares attacked in the other half52not castlednot castled

Codes that branch off from B20

The reference lines of four other codes leave B20 from the position after 1...c5, each with its own moves.

CodeMovesReference line
B212.f4Sicilian Defense: McDonnell Attack
B222.c3Sicilian Defense: Alapin Variation
B232.Nc3Sicilian Defense: Closed
B272.Nf3Sicilian Defense

Closest boards in other codes

CodeLineDiffers on
B10Caro-Kann Defensetwo squares: c5, c6
A30English Opening: Symmetrical Variationfour squares: c2, e2, c4, e4
A43Benoni Defense: Old Benonifour squares: d2, e2, d4, e4
B01Scandinavian Defensefour squares: c5, d5, c7, d7
B02Alekhine Defensefour squares: c5, f6, c7, g8
B06Modern Defensefour squares: c5, g6, c7, g7
B12Caro-Kann Defensefour squares: d2, d4, c5, c6

Where lines continue from here

Besides the codes above, they belong to B24, B25, B26, B28, B29, B30, B31, B32, B33, B34, B35, B36, B37, B38, B39, B40, B41, B42, B43, B44, B45, B46, B47, B48, B49, B50, 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, C30.

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

Volume C

  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

  • Sicilian Defense: Staunton-Cochrane Variation is also reached inside A36 English Opening: Symmetrical Variation, Botvinnik System, whose order is 1.c4 c5 2.e4.

Open this line in the finderAll Sicilian Defense codes