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 controlled approach to the game.