Such a name is a homage, an acknowledgment, a gratitude, a tribute that I want to make and dedicate to the Grand Father of all the chess variants inventors: to the Chaturanga's inventor, according the majority opinion of the chess historians.

A *sissa* moves like the knight in Coherent
Chess (another chess variant by Carlos Cetina), as follows:
in one turn, first, the sissa
moves one or more squares like a rook or a bishop, and then the sissa
moves the same number of squares like the other of the two (bishop or
rook.) So, the sissa has the following options:

- First, it moves a number of squares as a rook. Then it makes a corner of 45, 135, 225, or 315 degrees, and then moves the same number of squares as a bishop. All squares that are passed by must be empty, i.e., a sissa does not jump over pieces.
- First, it moves a number of squares as a bishop. Then, it makes a corner of 45, 135, 225, or 315 degrees, and then moves the same number of squares as a rook. Again, all squares passed by must be empty.

Bishops have, in addition to their normal diagonal
movement, one extra possibility
(which is, in a certain sense, also obligatory): the bishop moves one square
horizontally or vertically at the first time it moves during the game.
This may be done only once, with one of the
players bishops. Also, for one of the bishops of the player, the first move
made with this bishop must be of this special type. This move is called
*conversion*. Note that a player may choose which bishop he converts,
but if he makes a normal move with one of his bishops, the first move made
with the other bishop must be a conversion move. Note also that a player
never can make more than one conversion move in a game, and a promoted
bishop does not make conversion moves. It is possible to take a piece of
the opponent by conversion. (See also a
more detailed description of this `Bishops Conversion rule'.)

The other pieces move like in usual chess. Kings always move three squares when castling, the rook jumping over them to the next square. Pawns may promote to queen, rook, knight, bishop, or sissa, to the owning players choice when they reach the last row.

Villahermosa, Mexico; February 1998.

Comments by Carlos Cetina

Note: Castling is described only by the king's movement.

1.e4 e6 2.d4 f6 3.c4 Ng7 4.Nc3 Bb4 5.Qb3 Qf8 6.a3 Bxc3+ 7.bxc3[Note the b8-pawn is not protected, since the first movement of the c9- bishop must necessarily be toward b9, c8 or d9]

7. ... c6[Now the d9-sissa protects the b8-pawn by the path d9-c8-b8]

8.h3 Nc7 9.Bh2 Kh9 10.Se3[Path: f1-e2-e3]

10. ... Bc8[Now the b8-pawn is protected by the d9-sissa by the path d9-c9-b8, not by d9-c8-b8 since the c8-bishop now obstructs this path]

11.f4 d6 12.Nf2 b7 13.Kh1 Nge8 14.Bc2 Se7[Path: d9-d8-e7]

15.Rae1 g6 16.Rgf1 Rg7 17.f5 Rag9 18.fxe6 Bxe6 19.d5 Bg8 20.Sa5[Path: e3-c5-a5]

20. ... Ri7 21.Ng4 c5 22.e5 f5??[22. ... Nxd5! 23.Sxe7 (path a5-c7-e7; 23.cxd5?? Sxa5) 23. ... Nxe7 24.exf6 Nc6 25.Bxg6 Bf7 26.Be4 Na5 27.Qd1 Nxc4 and the coin is gyrating at the air yet!]

23.exd6 Sd7[Path: e7-d8-d7 or e7-e6-d7]

24.dxc7 Nf6 25.Nxf6 Qxf6 26.Bd1 g5 27.Qc2 f4 28.Bg4 Sxc7[Path: d7-c6-c7 or d7-c8-c7 or d7-d6-c7 or d7-d8-c7]

29.Sa4[Path: a5-b5-a4 or a5-b4-a4]

29. ... Bf9 30.Se6[Path: a4-c6-e6]

30. ... Qxe6 31.Bxe6+ Bg8 32.Bxg8+ Rxg8 33.Re9+ Rg9 34.Rxg9+ Kxg9 35.Qg6+[35.g3?? Sxc2 (path c7-h7-c2)]

35. ... Rg7 36.Qd6+ Kg8 37.Bg1 Sxa3[Path: c7-a5-a3]

38.Bxc5 Sxc3?![Path: a3-a5-c3 or a3-a1-c3 or a3-c1-c3; it was better 38. ... Sxc4 by the paths a3-b3-c4 or a3-b4-c4]

39.Bd4 Sxc4[Path: c3-b4-c4 or c3-b3-c4 or c3-d3-c4. The path c3-d4-c4, obviously, is obstructed by the d4-bishop. If 39. ... Sb3!? attacking both d4-bishop and f1-rook (this last by b3-d1-f1 or b3-d3-f1), then by all manners after 40.Bxg7 Sxf1 41.Qf8+ Kh7 42.Qxh8+ Kg6 43.Qh6+ Kf7 44.Qf6+ Kg8 45.Qf8+ Kh7 46.Bi5, Black would follow being lost]

40.Qe6+ Kh7 41.Bxg7 hxg7 42.d6 Sd2[Normal FIDE-knight movement attacking the f1-rook]

43.Re1 Sf2+[Path: d2-d4-f2; giving check by f2-g1-h1]

44.Kg1?[Better 44.Kh2]

44. ... Sxi2+[Path: f2-i5-i2; giving check at the same time by i2-h2-g1 and i2-h1- g1]

45.Kh1 Si3+[Path: i2-h2-i3]

46.Kh2 Sg3[Path: i3-i5-g3]

47.d7 Sc5[Path: g3-e3-c5]

48.Qe8 f3 49.d8 Sc2+[Path: c5-f2-c2 or c5-f5-c2; giving check by c2-c7-h2]

50.g3[Obstructing the c7-h2 diagonal]

50. ... Sd4+[Giving check by d4-f2-h2]

51.Ki2 f2 52.d9=S+[Giving check by d9-f9-h7]

52. ... Ki7 53.Sh9+[Path: d9-d5-h9; giving check as normal knight]

53. ... Ki6[Unique. The h9-sissa covers the squares h8 (by the paths h9-g9-h8 or h9-i9-h8 or h9-g8-h8), h7 (by the path h9-f9-h7) and h6 (by the path h9-e6-h6)]

54.Qh5 mate!!![The h9-sissa protects the queen by the path h9-d9-h5 and, of course, covers the i7-square as normal knight]

Written by Hans Bodlaender and Carlos Cetina.

WWW page created: March 10, 1998. Last modified: March 17, 1998.