Differences

This shows you the differences between two versions of the page.

--- chess4 [2013/11/20 11:56]
dlicious Added "can't move your King into check" rule and changed/clarified checkmate rule
+++ chess4 [2014/02/20 19:25] (current)
dlicious Added complete (example) PGN files and extra information gained from first playthrough
@@ Line 69: / Line 69: @@
 ===== Game Notation =====
-As we play through [[http://www.daaave.org/chess4/firstgame|our first full Chess4 game]], I'm trying to work up a Chess4-specific PGN sub-format. It won't be directly usable by current PGN parsers of course, but any human reading the file (who's familiar with Chess4 and PGN files) should immediately understand what's going on. My goals with the format are to maintain that familiarity while requiring the smallest adjustment possible if a piece of software ever did want to support the format.  The example below just goes through the fourth turn, so I'm not constantly filling this wiki page's edit history up by adding moves; once the game finishes I'll update the whole thing at once and until then you can see [[http://www.daaave.org/chess4/firstgame/firstgame.pgn.txt|the current PGN for the game in progress]].
+Now that we've played through [[http://www.daaave.org/chess4/firstgame|our first full Chess4 game]], I'm putting the finishing touches on a Chess4-specific PGN sub-format. It won't be directly usable by current PGN parsers of course, but any human reading the file (who's familiar with Chess4 and PGN files) should immediately understand what's going on. My goals with the format are to maintain that familiarity while requiring the smallest adjustment possible if a piece of software ever did want to support the format.  The example below just goes through the fourth turn, so I'm not constantly filling this wiki page's edit history up by adding moves; once the game finishes I'll update the whole thing at once and until then you can see [[http://www.daaave.org/chess4/firstgame/firstgame.pgn.txt|the current PGN for the game in progress]].
+==== Incremental scoring ====
+  * A player is awarded one point for eliminating another player
+  * A player is awarded half a point for stalemating another player
+  * A player is awarded half a point for being stalemated
+  * When a player resigns, one point is divided evenly between the remaining players
+==== Result lookup table ("Last Man Standing" scoring) ====
+This is just a quick lookup table for the "Result" header.  I wanted to stay consistent with regular PGN (by using "1/2" intead of "0.5"), but it just got weird when I had to deal with something like "1-1/2" when the separator character between players is already "-" (although, could do something like "1+1/2"; might need to anyway for the "incremental" scoring since it can produce thirds of a point).  What may work is to double all the values so there are no halves...honestly, figuring out what the values of the numbers need to be for proper scoring ratios is probably a job for someone with a much more extensive chess background.
+Don't forget when copy/pasting the Result header into your PGN; you need to rearrange the values to match the actual result of your game.  In other words, the scores are always in the order of "White-Silver-Black-Gold" (just like in regular PGN where "1-0" always means that White won).
+^ 1st        ^ 2nd          ^ 3rd        ^ 4th  ^ Result header                      ^ Notes                                ^
+|  3         |  2           |  1         |  0   | [ "Result" "3-2-1-0" ]             | No ties                              |
+|  3         |  1                             ||| [ "Result" "3-1-1-1" ]             | 3-way tie for 2nd                    |
+|  3         |  2           |  0.5             || [ "Result" "3-2-1/2-1/2" ]         | 2-way tie for 3rd                    |
+|  3         |  1.5                     ||  0   | [ "Result" "3-1+1/2-1+1/2-0" ]     | 2-way tie for 2nd                    |
+|  2.5                     ||  0.5             || [ "Result" "2+1/2-2+1/2-1/2-1/2" ] | 2-way tie for 1st, 2-way tie for 3rd |
+|  1                                   |||  0   | [ "Result" "1-1-1-0" ]             | 3-way tie for 1st                    |
+==== Deviations from standard PGN ====
+  - The "Result" header is in a different format
+  - Colors always go in order: White, Silver, Black, Gold
+  - Some extensions to algebraic notation are necessary:
+    - The '#' and '##' notations for check and checkmate are now followed by one or more of the letters "wsbg" to denote which color(s) has been checked or checkmated
+    - The 'o-o' and 'o-o-o' castling notations have been extended to include the color of pieces used (in case a player is castling another eliminated player's pieces)
+    - A new notation to specify an untaken turn (by an eliminated player)
+==== Example move notations (c4pgn extensions marked with '[*]') ====
+^ Notation             ^ Notes                                                                         ^
+| k7                   | Pawn moves are specified with just the destination square                     |
+| gxk7                 | Pawn capture with disambiguating origination file                             |
+| 8xk7                 | Pawn capture with disambiguating origination rank                             |
+| g8xk7                | Pawn capture with disambiguating origination rank and file                    |
+| Nl13                 | Knight move                                                                   |
+| o-o-w                | King-side castle using White's pieces [*]                                     |
+| o-o-o-s              | Queen-side castle using Silver's pieces [*]                                   |
+| Nji12#g              | Knight (on file J) moves to I12, checking Gold [*]                            |
+| Qf3xb7#g##bw         | Queen on F3 captures on B7, checking Gold and checkmating Black and White [*] |
+| Qxb9#b##w###g        | Queen captures on b9, checks black, checkmates white, and eliminates gold [*] |
+| %                    | Pieces unable to move due to check/checkmate [*]                              |
+| <nowiki>%%</nowiki>  | Player resigns [*]                                                            |
+| <nowiki>%%%</nowiki> | Placeholder for an eliminated player's turn [*]                               |
+==== Example PGN files ====
+Here are two example PGN files for completed games.  They're actually both for the same game; the first one is written up with my (decidedly-amateur) annotations, and also contains all the extra "fluff" notation (using x to denote captures, annotating check/checkmate/elimination with #/##/###, etc.).  This is the one you should look at if you want to actually follow the game, or be led gently when developing a parser.  The second version is the same PGN with all comments and non-derivable information stripped; it's intended as an "acid test" for a c4pgn parser.  Any feature-complete Chess4 engine should be able to take "firstgame-condensed.pgn" as input and produce "firstgame.pgn" as output (in other words, derive and populate the extra annotations from the remaining data).  Well, without my Lord of the Rings-inspired color commentary, of course.
 <file pgn firstgame.pgn>
-[ White                "Blinky"                                               ]
+[ Variant              "Chess4"                                               ]
-[ Silver               "Pinky"                                                ]
+[ Variant-Version      "1.0"                                                  ]
-[ Black                "Inky"                                                 ]
+[ Notation-Style       "c4pgn"                                                ]
+[ Notation-Version     "1.0"                                                  ]
+[ White                "Inky"                                                 ]
+[ Silver               "Blinky"                                               ]
+[ Black                "Pinky"                                                ]
 [ Gold                 "Clyde"                                                ]
 [ Date                 "2013.09.18"                                           ]
 [ Date-Started         "2013.09.18"                                           ]
-[ Date-Ended           ""                                                     ]
+[ Date-Ended           "2014.02.20"                                           ]
-[ White-Eliminated-By  ""                                                     ]
+[ White-Eliminated-By  "Silver"                                               ]
 [ Silver-Eliminated-By ""                                                     ]
 [ Black-Eliminated-By  ""                                                     ]
-[ Gold-Eliminated-By   ""                                                     ]
+[ Gold-Eliminated-By   "Silver"                                               ]
-[ Result               "1/4-1/4-1/4-1/4&quot;                                      ]
+[ Result               "0-3-1-2"                                              ]
+[ Result-Second-Format "0-6-2-4"                                              ]
+.  k7        { M7  > K7  } { White  }
+    Nk3       { J1  > K3  } { Silver }
+    d8        { B8  > D8  } { Black  }
+    h11       { H13 > H11 } { Gold   }
+.  Bk9       { N6  > K9  }
+    Nd3       { E1  > D3  }
+    Nc6       { A5  > C6  }
+    Nf12      { E14 > F12 }
+.  k10       { M10 > K10 }
+    e4        { E2  > E4  }
+    c4        { B4  > C4  }
+    Qxk10     { G14 > K10 }
+.  l9        { M9  > L9  }
+    Nf4       { D3  > F4  }
+    d4        { C4  > D4  }
+    Qxk9      { K10 > K9  }
+.  l8        { M8  > L8  }
+    Ne6       { F4  > E6  }
+    Bb8       { A9  > B8  }
+    Qj10      { K9  > J10 }
+.  Nl11      { N10 > L11 }
+    Be2       { F1  > E2  }
+    d10       { B10 > D10 }
+    Qe10      { J10 > E10 }
+.  Nl6       { N5  > L6  }
+    O-O       { G1  > E1 / D1  > F1 }
+    d7        { B7  > D7  }
+    { [A(Clyde)
+    For Black's own sake, I hope he's not planning on
+    ( 8. ... ... Bxi14 ), because that leaves him open to ( 9. ... Bxb5 ),
+    which leads to the loss of a pawn and knight
+    ( 9. ... Bxb5 Ra5 ... 10. ... Bxc6 ) followed by the loss of the ability
+    to castle ( 10. ... ... Ka9 ) or a bishop trade
+    ( 10. ... ... Bb7 ... 11. ... Bxb7 Qxb7 ).  Although, Silver might avoid
+    the bishop trade since there are more than two players to think about.
+    ] }
+    Qf10      { E10 > F10 }
+.  Rn10      { N11 > N10 }
+    Ng5       { E6  > G5  }
+    Bxi14?    { A6  > I14 }
+    Kxi14??   { H14 > I14 }
+    { [A(Clyde)
+    I wish I could say I had some grand strategy here, but no; I just wasn't
+    paying attention. :(
+    ] }
+.  Rxf10     { N10 > F10 }
+    Bxl9??    { E2  > L9  }
+    Bf4       { B8  > F4  }
+    Nh13      { J14 > H13 }
+. Bm8       { N9  > M8  }
+    Be2       { L9  > E2  }
+    Qa6       { A7  > A6  }
+    g12       { G13 > G12 }
+. Nj7       { L6  > J7  }
+    Nh3       { G5  > H3  }
+    Bb8       { F4  > B8  }
+    Nd11      { F12 > D11 }
+. Rxf13     { F10 > F13 }
+    Bxj7      { E2  > J7  }
+    Qxg12     { A6  > G12 }
+    Nf12      { D11 > F12 }
+    { [A(Clyde)
+    Well, that sucked.  Have to move back to avoid checkmate by protecting
+    H13...
+    ] }
+. Rxh13     { F13 > H13 }
+    Be2       { J7  > E2  }
+    O-O-O     { A8  > A6 / A4  &gt; A7  }
+    Bg13      { F14 > G13 }
+. Rxi13     { H13 > I13 }
+    Bm10      { E2  > M10 }
+    d11       { B11 > D11 }
+    Kj14      { I14 > J14 }
+. Nk9       { L11 > K9  }
+    Be2       { M10 > E2  }
+    e11       { D11 > E11 }
+    j12       { J13 > J12 }
+. Ri8       { I13 > I8  }
+    j3        { J2  > J3  }
+    xf12      { E11 > F12 }
+    Bxf12     { G13 > F12 }
+. Ri14??    { I8  > I14 }
+    Bj2       { I1  > J2  }
+    Rxh11     { A11 > H11 }
+    Rxi14     { D14 > I14 }
+. O-O       { N7  > N5 / N4  > N6  }
+    Bg5       { J2  > G5  }
+    Rxm11     { H11 > M11 }
+    Kj13      { J14 > J13 }
+. Ni10      { K9  > I10 }
+    Bxm11     { G5  > M11 }
+    Nc11      { A10 > C11 }
+    d12       { D13 > D12 }
+. Nh8       { I10 > H8  }
+    Bh6       { M11 > H6  }
+    Nd13      { C11 > D13 }
+    Bi9       { F12 > I9  }
+. Nf7       { H8  > F7  }
+    Bj4       { H6  > J4  }
+    Ra11      { A7  > A11 }
+    Bj10      { I9  > J10 }
+. k5        { M5  > K5  }
+    Bi3       { J4  > I3  }
+    Rj11      { A11 > J11 }
+    Rd14      { I14 > D14 }
+. l4??      { M4  > L4  }
+    { [A(Clyde)
+    Well, that's...interesting.  I pretty much based my entire strategy for the
+    previous move on the assumption that White would, you know, take the free
+    rook that Black served up on a platter.
+    ] }
+    Ni4       { K3  > I4  }
+    Qg11#g    { G12 > G11 }
+    Ki13
+. Bxj11     { M8  > J11 }
+    j4        { J3  > J4  }
+    e8        { D8  > E8  }
+    Bh12      { J10 > H12 }
+. Nh8       { F7  > H8  }
+    xk5       { J4  > K5  }
+    Qe12      { G10 > E12 }
+    Bg11      { H12 > G11 }
+. Bm8       { J11 > M8  }
+    Rj1       { K1  > J1  }
+    Bc7       { B8  > C7  }
+    Rkg14     { K14 > G14 }
+. Bxi4      { M8  > I4  }
+    k6        { K5  > K6  }
+    Qxe13#g   { E12 > E13 }
+    Kh14      { I13 > I14 }
+    { [A(Clyde)
+    Really grasping at straws here...I'd like to think about Bi13 at some
+    point, to protect myself from White's Queen; I thought about
+    ( 27. ... ... ... Ki14 ) but I need the extra protection so I can do
+    Rg13 to threaten White's Queen and still protect the piece...otherwise
+    Black will get a lot more than a free Bishop.
+    ] }
+. Bxk6??    { I4  > K6  }
+    Bxn8      { I3  > N8  }
+    Bxg11     { C7  > G11 }
+    Rde14     { D14 > E14 }
+. Rxn8      { N6  > N8  }
+    Rj4       { J1  > J4  }
+    Bf12#g    { G11 > F12 }
+    Ki14      { H14 > I14 }
+. Bf11#bg   { K6  > F11 }
+    Rj5#w     { J4  > J5  }
+    e10       { D10 > E10 }
+    Kj14      { I14 > J14 }
+. Kn6       { N5  > N6  }
+    Qi1       { H1  > I1  }
+    Bg11#g    { F12 > G11 }
+    Rxg11     { G14 > G11 }
+. Bk6       { F11 > K6  }
+    Rxb5      { J5  > B5  }
+    Qxe14#g   { E13 > E14 }
+    Ki13      { J14 > I13 }
+. Rn9       { N8  > N9  }
+    Qxl4#w    { I1  > L4  }
+    Na7       { C6  > A7  }
+    Re11      { G11 > E11 }
+. Kn7       { N6  > N7  }
+    Rk5#b?!   { B5  > K5  }
+    { [A(Clyde::?!)
+    Interesting that this wasn't ( 34. ... Ri5#bg ), although now that I think
+    about it, it was probably deliberate; by not putting me in check, he
+    enabled me to take Black's Queen (which is good for him).  Still, this
+    breathed new life into what was pretty much looking like an impending
+    checkmate.
+    Hold your ground! Hold your ground!
+    Sons of Gold, my brothers,
+    I see in your eyes the same fear that would take the heart of me.
+    A day may come when the courage of Gold fails,
+    when we forsake our Pawns
+    and break all bonds of piece protection,
+    but it is not this day.
+    An hour of silver Rooks and shattered pawn structure,
+    when the age of Gold comes crashing down,
+    but it is not this day!
+    This day we fight!!
+    By all that you hold dear on this good Earth,
+    I bid you stand, men of the Gold!!!
+    ] }
+    Nb5       { A7  > B5  }
+    Rxe14     { E11 > E14 }
+. Bxd13     { K6  > D13 }
+    Rxb5      { K5  > B5  }
+    Kb7       { A6  > B7  }
+    Rj14      { E14 > J14 }
+. Rxb9#b    { N9  > B9  }
+    Rn5#w     { B5  > N5  }
+    Kc8       { B7  > C8  }
+    k11       { K13 > K11 }
+. Km7       { N7  > M7  }
+    Qxh8      { L4  > H8  }
+    Kxb9      { C8  > B9  }
+    d11       { D12 > D11 }
+. Bm4       { D13 > M4  }
+    Rn9#b     { N5  > N9  }
+    Kc8       { B9  > C8  }
+    k10       { K11 > K10 }
+. Bk6       { M4  > K6  }
+    Qk5#w     { H8  > K5  }
+    c6        { B6  > C6  }
+    j11       { J12 > J11 }
+. Kl7       { M7  > L7  }
+    Rj1       { F1  > J1  }
+    f10       { E10 > F10 }
+    j10       { J11 > J10 }
+. l6        { M6  > L6  }
+    Qn5#w     { K5  > N5  }
+    g10       { F10 > G10 }
+    j9        { J10 > J9  }
+. Km8       { L7  > M8  }
+    Qn7##w    { N5  > N7  }
+    h10       { G10 > H10 }
+    Rk14      { J14 > K14 }
+. %s        { White checkmated by silver and forced to pass }
+    Ba6#b###w { E2  > A6  }
+    Kc7       { C8  > C7  }
+    j7        { J8  > J7  }
+. %%%
+    Qn5       { N7  > N5  }
+    Kd6       { C7  > D6  }
+    j6        { J7  > J6  }
+. %%%
+    Qi10#g    { N5  > I10 }
+    Ke5       { D6  > E5  }
+    Kh12      { I13 > H12 }
+. %%%
+    Rj4       { J1  > J4  }
+    d6        { C6  > D6  }
+    k9        { K10 > K9  }
-. k7      { M7  > K7  } { White  }
+. %%%
-   Nk3     { J1  > K3  } { Silver }
+    Rh4       { J4  > H4  }
-   d8      { B8  > D8  } { Black  }
+    e7        { D7  > E7  }
-   h11     { H13 > H11 } { Gold   }
+    xl8       { K9  > L8  }
-. Bk9     { N6  > K9  }
+. %%%
-   Nd3     { E1  > D3  }
+    Rxh10#g   { H4  > H10 }
-   Nc6     { A5  > C6  }
+    Kxe4      { E5  > E4  }
-   Nf12    { E14 > F12 }
+    Kg11      { H12 > G11 }
-. k10     { M10 > K10 }
+. %%%
-   e4      { E2  > E4  }
+    Rn11#g    { N9  > N11 }
-   c4      { B4  > C4  }
+    f7        { E7  > F7  }
-   Qxk10   { G14 > K10 }
+    Kf12      { G11 > F12 }
-. l9      { M9  > L9  }
+. %%%
-   Nf4     { D3  > F4  }
+    Qi12#g    { I10 > I12 }
-   d4      { C4  > D4  }
+    f8        { E8  > F8  }
-   Qxk9    { K10 > K9  }
+    Kg13      { F12 > G13 }
-{ -----------------------------------------------------------------------------
+. %%%
+    Rh13      { H10 > H13 }
+    g8        { F8  > G8  }
+    Kg14      { G13 > G14 }
-Deviations from standard PGN:
+. %%%
+    Rxd11     { N11 > D11 }
+    Ke5       { E4  > E5  }
+    Rh14      { J14 > H14 }
-  - The &quot;Result&quot; header is in a different format (specifics TBD)
+. %%%
-  - The '#' and '##' notations for check and checkmate are now followed by
+    Qe12#bg   { I12 &gt; E12 }
-    one or more of the letters &quot;wsbg" to denote which color(s) has been
+    e6        { D6  &gt; E6  }
-    checked or checkmated
+    Kf14      { G14 &gt; F14 }
-  - The 'o-o' and 'o-o-o' castling notations have been extended to include
-    the color of pieces used (in case a player is castling another eliminated
-    player's pieces)
-  - A new notation to specify an untaken turn (by an eliminated player)
+. %%%
+    Rd14##g   { D11 > D14 }
+    e4        { D4  > E4  }
+    %s        { Gold checkmated by Silver and forced to pass }
-Example move notations (Chess4 extensions marked with '[*]'):
+. %%%
+    Kd1###g   { Gold eliminated by Silver }
+    %%        { Black resigns }
-  k7           - Pawn moves are specified with just the destination square
+-3-1-2   { Result: "Last Man Standing" scoring }
-  gxk7         - Pawn capture with disambiguating origination file
+-3-0-0   { Result: Incremental scoring }
-xk7         - Pawn capture with disambiguating origination rank
+</file>
-  g8xk7        - Pawn capture with disambiguating origination rank and file
-  Nl13         - Knight move
-  o-o-w        - King-side castle using White's pieces [*]
-  o-o-o-s      - Queen-side castle using Silver's pieces [*]
-  Nji12#g      - Knight (on file J) moves to I12, checking Gold [*]
-  Qf3xb7#g##bw - Queen on F3 captures on B7, checking Gold and checkmating
-                 Black and White [*]
-  Qxb9###      - Queen captures on b9 and checkmates all remaining players [*]
-            - Placeholder for a turn not taken due to player elimination [*]
------------------------------------------------------------------------------ }
+<file pgn firstgame-condensed.pgn>
+[ Variant "Chess4" ]
+[ Variant-Version "1.0" ]
+[ Notation-Style "c4pgn" ]
+[ Notation-Version "1.0" ]
+[ White "Inky" ]
+[ Silver "Blinky" ]
+[ Black "Pinky" ]
+[ Gold "Clyde" ]
+[ Date "2013.09.18" ]
+[ Date-Started "2013.09.18" ]
+[ Date-Ended "2014.02.20" ]
+[ Result "0-3-1-2" ]
-{ EOF }
+. k7 Nk3 d8 h11 2. Bk9 Nd3 Nc6 Nf12 3. k10 e4 c4 Qk10 4. l9 Nf4 d4 Qk9 5. l8 Ne6 Bb8 Qj10 6. Nl11 Be2 d10 Qe10 7. Nl6 O-O d7 Qf10 8. Rn10 Ng5 Bi14 Ki14 9. Rf10 Bl9 Bf4 Nh13 10. Bm8 Be2 Qa6 g12 11. Nj7 Nh3 Bb8 Nd11 12. Rf13 Bj7 Qg12 Nf12 13. Rh13 Be2 O-O-O Bg13 14. Ri13 Bm10 d11 Kj14 15. Nk9 Be2 e11 j12 16. Ri8 j3 f12 Bf12 17. Ri14 Bj2 Rh11 Ri14 18. O-O Bg5 Rm11 Kj13 19. Ni10 Bm11 Nc11 d12 20. Nh8 Bh6 Nd13 Bi9 21. Nf7 Bj4 Ra11 Bj10 22. k5 Bi3 Rj11 Rd14 23. l4 Ni4 Qg11 Ki13 24. Bj11 j4 e8 Bh12 25. Nh8 k5 Qe12 Bg11 26. Bm8 Rj1 Bc7 Rkg14 27. Bi4 k6 Qe13 Kh14 28. Bk6 Bn8 Bg11 Rde14 29. Rn8 Rj4 Bf12 Ki14 30. Bf11g Rj5 e10 Kj14 31. Kn6 Qi1 Bg11 Rg11 32. Bk6 Rb5 Qe14 Ki13 33. Rn9 Ql4 Na7 Re11 34. Kn7 Rk5 Nb5 Re14 35. Bd13 Rb5 Kb7 Rj14 36. Rb9 Rn5 Kc8 k11 37. Km7 Qh8 Kb9 d11 38. Bm4 Rn9 Kc8 k10 39. Bk6 Qk5 c6 j11 40. Kl7 Rj1 f10 j10 41. l6 Qn5 g10 j9 42. Km8 Qn7 h10 Rk14 43. % Ba6 Kc7 j7 44. %%% Qn5 Kd6 j6 45. %%% Qi10 Ke5 Kh12 46. %%% Rj4 d6 k9 47. %%% Rh4 e7 l8 48. %%% Rh10 Ke4 Kg11 49. %%% Rn11 f7 Kf12 50. %%% Qi12 f8 Kg13 51. %%% Rh13 g8 Kg14 52. %%% Rd11 Ke5 Rh14 53. %%% Qe12g e6 Kf14 54. %%% Rd14 e4 % 55. %%% Kd1 %% 0-3-1-2 0-3-0-0
 </file>