In cricket, the batting order is the sequence in which batters play through their team's innings, there always being two batters taking part at any one time. All eleven players in a team are required to bat if the innings is completed (i.e., if the innings does not close early due to a declaration or other factor). The batting order is colloquially subdivided into: Top order (batters one to four) Middle order (batters four to eight; which can also be divided into:) Upper Middle order (batters four to six) Lower Middle order (batters six to eight) Tail Enders (batters nine to eleven) The order in which the eleven players will bat is usually established before the start of a cricket match, but may be altered during play. The decision is based on factors such as each player's specialities; the position each batter is most comfortable with; each player's skills and attributes as a batter; possible combinations with other batters; and the match situation whereby, for example, the team may require a more defensive or attacking player at that point in the innings. Also, a middle order batter in Tests may open for ODIs and Twenty20 due to their aggressive approach to the game.