with the better pawn structure. When playing against stronger players, many beginners attempt to constantly exchange pieces "to simplify matters". However, stronger players are often relatively stronger in the endgame, whereas errors are more common during the more complicated middlegame. Note that "the exchange" may also specifically mean a rook exchanged for a bishop or knight. The phrase, "going up the exchange," means capturing a rook in exchange for a bishop or knight as that is a materially better trade. Conversely, "going down an exchange," means losing a rook but capturing a bishop or knight, a materially worse trade. Specific pieces Pawns In the endgame, passed pawns, unhindered by enemy pawns from promotion, are strong, especially if advanced or protected by another pawn. A passed pawn on the sixth is roughly as strong as a knight or bishop and often decides the game. (Also see isolated pawn, doubled pawns, backward pawn, connected pawns.) Knights Since knights can easily be chased away by pawn moves, it is often advantageous for knights to be placed in in the enemy position as outposts—squares where they cannot be attacked by pawns. Such a knight on the fifth rank is a strong asset. The ideal position for a knight is the opponent's third rank, when it is supported by one or two pawns. A knight at the edge or corner of the board controls fewer squares than one on the board's interior, thus the saying: "A Knight on the rim is dim!" A king and one knight is not sufficient material to checkmate an opposing lone king (see Two knights endgame). A king and two knights can checkmate a lone king but it cannot be forced. Bishops A bishop always stays on squares of the color it started on, so once one of them is gone, the squares of that color become more difficult to control. When this happens, pawns moved to squares of the other color do not block the bishop, and enemy pawns directly facing them are stuck on the vulnerable color. A fianchettoed bishop, e.g. at g2 after pawn g2–g3, can provide a strong defense for the castled king on g1 and often exert pressure on the long diagonal h1–a8. After a fianchetto, giving up the bishop can weaken the holes in the pawn chain; doing so in front of the castled king may thus affect its safety. In general, a bishop