 An example of inefficiency or poor coordination of stones in the context of connection is the empty triangle, where the stones are arranged so that they share fewer liberties than if they were deployed in a straight line.A key concept in the tactics of Go, though not part of the rules, is the classification of groups of stones into "alive", "dead" or "unsettled".At the end of the game, groups that cannot avoid being captured during normal play are removed as captures.