every square on the file. If one file is particularly important, a player might advance one rook on it, then position the other rook behind—doubling the rooks. A rook on the seventh rank (the opponent's second rank) is typically very powerful, as it threatens the opponent's unadvanced pawns and hems in the enemy king. A rook on the seventh rank is often considered sufficient compensation for a pawn. In the diagrammed position from a game between Lev Polugaevsky and Larry Evans, the rook on the seventh rank enables White to draw, despite being a pawn down. Two rooks on the seventh rank are often enough to force victory by the blind swine mate, or at least a draw by perpetual check. Endgame Rooks are most powerful towards the end of a game (i.e., the endgame), when they can move unobstructed by pawns and control large numbers of squares. They are somewhat clumsy at restraining enemy pawns from advancing towards promotion unless they can occupy the file behind the advancing pawn. As well, a rook best supports a friendly pawn towards promotion from behind it on the same file (see Tarrasch rule). In a position with a rook and one or two versus two rooks, generally in addition to pawns, and possibly other pieces, Lev Alburt advises that the player with the single rook should avoid exchanging the rook for one of his opponent's rooks. The rook is adept at delivering checkmate. Below are a few examples of rook checkmates that are easy to . A single rook can force checkmate while a single minor piece cannot. History In the medieval shatranj, the rook symbolized a chariot. The Persian word rukh means "chariot", and the corresponding piece in the original Indian version, chaturanga, has the name ratha (meaning "chariot"). In modern times it is mostly known as हाथी (elephant) to Hindi-speaking players, while east-Asian chess games such as xiangqi and shogi have names also meaning chariot (車) for the same piece. Persian war-chariots were heavily armored, carrying a driver and at least one ranged-weapon bearer, such as an archer. The sides of the chariot were built to resemble fortified stone work, giving the impression of small, mobile buildings, causing terror on the battlefield. In Europe the castle or tower appears for the first time in the 16th century in Vida's 1550 Ludus Scacchia, and then as a tower on the back