Exchange (chess) to as a "recapture". Commonly, the word "exchange" is used when the pieces exchanged are of the same type or of about equal value, which is an "even exchange". According to chess tactics, a bishop and a knight are usually of about equal value. If the values of the pieces exchanged are not equal, then the player who captures the higher value of piece(s) can be said to be "up the exchange" or "wins the exchange", while the opponent who captures the lower value of piece(s) is "down the exchange" or "loses the exchange". Exchanges occur very frequently in chess,
Evolution of the horse horse", "Orohippus" was not a true horse and did not live in the mountains. It resembled "Eohippus" in size, but had a slimmer body, an elongated head, slimmer forelimbs, and longer hind legs, all of which are characteristics of a good jumper. Although "Orohippus" was still pad-footed, the vestigial outer toes of "Eohippus" were not present in "Orohippus"; there were four toes on each fore leg, and three on each hind leg. The most dramatic change between "Eohippus" and "Orohippus" was in the teeth: the first of the premolar teeth were dwarfed, the last premolar shifted in shape and function