User:Ihardlythinkso/Chess endgame lede by JacquesDelaguerre

Chess endgame
The chess endgame (or end game or ending) is a non-rigorous term referring to the stage of the game when the strategic patterns laid out in the opening and executed in the middlegame have not led to sudden checkmate and the cumulative effect of irreversible piece capture (unlike chess's Japanese cognate shogi in which pieces return) has resulted in a reduced number of pieces remaining on the board in a position progressively more subject to concrete calculation by highly skilled players and especially by chess-playing computers.

The line between middlegame and endgame is subjective, and may occur gradually or with the quick exchange of a few pairs of pieces. The endgame differs from the middlegame in a number of respects. By the time the ending is reached, the plethora of variations have liberated the position of the pieces (excepting any pawns remaining) from most perceptible dependence on the original starting position. All-or-nothing assaults on the opposing king are less likely and the individual pieces come into their own, especially the rooks whose corner starting position makes them late entrants into the game. Thus the endgame exhibits strategic concerns which differ markedly from the middlegame. In particular, pawns become more important: often neither side can muster a decisive advantage without promoting a pawn by advancing it to the eighth rank. The king, which must be sequestered in the middlegame owing to the threat of checkmate on a densely populated board, becomes a strong piece in the endgame. It may be brought to the center of the board and used as an attacking piece.

The science of game theory places chess among those intrinsically difficult problems which may only be solved back-to-front. Since each move towards the final position greatly reduces combinatorial complexity, chess endgame theory has for centuries been the most definitive field of chess study. In recent years an astronomical number of endgame positions have undergone exhaustive machine analysis and the results are stored in tablebases. This is in contrast to chess opening theory which is too combinatorially complex for exhaustive computation by present-day machines and remains dependent on heuristics.

Outstanding players throughout history have considered endgame study to be of paramount importance, as a player without endgame knowledge cannot accurately assess a chess midgame position from which a forced path to checkmate is absent. Furthermore, the endgame displays the power of the individual pieces with a clarity denied in earlier phases of the game by giving the individual pieces more scope on a sparsely populated board. Mastery of this definitive aspect of the game imparts epistemological insight into chess.

Many people have composed endgame studies, endgame positions which are solved by finding a win for White when there appears at first glance to be no obvious path to a win, or by finding a draw when it seems on casual perusal White must lose.

As very general rule in the endgame, the materially stronger side should try to exchange pieces (knights, bishops, rooks, and queens), while avoiding the exchange of pawns. This tends to makes it easier for for the stronger side to convert material advantage into a won game via pawn promotion. The defending side should strive for the opposite, the exchange of pawns and retention of pieces, as even an extra knight or bishop possessed by the opposing side is often insufficient to force checkmate in the absence of pawns.

Endgames can be classified according to the type of pieces that remain. Some common types of endgames are discussed below.

Checkmate
From the lede as of January 31, 2014:"The symbol '++' is sometimes used, but rarely. It can also mean double check."

After this edit by User:Mann jess on February 1, 2014:"The symbol '++' is also, rarely, used, but it can also mean double check."