Editing Chess endgame (section)

==Endgame classification==

Endgames can be classified by the material on the board. The standard classification system lists each player's material, including the kings, in the following order: king, queen, bishops, knights, rooks, pawn. Each piece is designated by its [[Algebraic chess notation#Naming the pieces|algebraic symbol]].

For example, if White has a king and pawn, and Black has only a king, the endgame is classified '''KPK'''. If White has bishop and knight, and Black has a rook, the endgame is classified '''KBNKR'''. KNBKR would not be standard.

In positions with two or more bishops on the board, a "bishop signature" may be added to clarify the relationship between the bishops. Two methods have been used. The informal method is to designate one color of squares as "x" and the other color as "y". An endgame of KBPKB can be written '''KBPKB x-y''' if the bishops are opposite-colored, or '''KBPKB x-x''' if the bishops are same-colored. The more formal method is to use a four digit suffix of the form '''abcd''':
*'''a''' = number of White light-squared bishops
*'''b''' = number of White dark-squared bishops
*'''c''' = number of Black light-squared bishops
*'''d''' = number of Black dark-squared bishops
Thus, the aforementioned endgame can be written '''KBPKB_1001''' for opposite-color bishops, and '''KBPKB_1010''' for same-color bishops.

In positions with one or more rooks on the board and where one or both players have one or both castling rights, a castling signature may be added to indicate which castling rights exist. The method is to use a one to four character suffix formed by omitting up to three characters from the string '''KQkq'''.

Thus the endgame where White has bishop and rook and Black has a rook can be written '''KBRKR''' if no castling rights exist or '''KBRKR_Kq''' if White may castle on the king's side and Black may castle on the queen's side. In case the position also has two or more bishops the castling signature follows the bishop signature as in '''KBBNKRR_1100_kq'''.

[[GBR code]] is an alternative method of endgame classification.

The ''Encyclopedia of Chess Endings'' (''ECE'') by [[Chess Informant]] had a different classification scheme, somewhat similar to the [[Encyclopaedia of Chess Openings|''ECO'' codes]], but it is not widely used. The full system is a 53-page index that was contained in the book ''The Best Endings of Capablanca and Fischer''. The code starts with a letter representing the most powerful piece on the board, not counting kings. The order is queen, rook, bishop, knight, and then pawn. (Figurines are used to stand for the pieces.) Each of these has up to 100 subclassifications, for instance '''R00''' through '''R99'''. The first digit is a code for the pieces. For instance, '''R0''' contains all endgames with a rook versus pawns and a rook versus a lone king, '''R8''' contains the double rook endgames, and '''R9''' contains the endings with more than four pieces. The second digit is a classification for the number of pawns. For instance, '''R30''' contains endgames with a rook versus a rook without pawns or with one pawn and '''R38''' are rook versus rook endings in which one player has two extra pawns.<ref>{{Cite web |url=http://www.gadycosteff.com/eg/eg90.pdf |title=ECE classifications, PDF of ''EG'' article |access-date=2009-02-03 |archive-url=https://web.archive.org/web/20090325092347/http://www.gadycosteff.com/eg/eg90.pdf |archive-date=2009-03-25 |url-status=dead }}</ref>