boots to increase traction. The kit is traditionally all white and this remains the case in Test and first-class cricket but, in limited overs cricket, team colours are worn instead. Bat and ball The essence of the sport is that a bowler delivers (i.e., bowls) the ball from his or her end of the pitch towards the batter who, armed with a bat, is "on strike" at the other end (see next sub-section: Basic gameplay). The bat is made of wood, usually Salix alba (white willow), and has the shape of a blade topped by a cylindrical handle. The blade must not be more than wide and the total length of the bat not more than . There is no standard for the weight, which is usually between 2 lb 7 oz and 3 lb (1.1 and 1.4 kg). The ball is a hard leather-seamed spheroid, with a circumference of . The ball has a "seam": six rows of stitches attaching the leather shell of the ball to the string and cork interior. The seam on a new ball is prominent and helps the bowler propel it in a less predictable manner. During matches, the quality of the ball deteriorates to a point where it is no longer usable; during the course of this deterioration, its behaviour in flight will change and can influence the outcome of the match. Players will, therefore, attempt to modify the ball's behaviour by modifying its physical properties. Polishing the ball and wetting it with sweat or saliva is legal, even when the polishing is deliberately done on one side only to increase the ball's swing through the air, but the acts of rubbing other substances into the ball, scratching the surface or picking at the seam are illegal ball tampering. Player roles Basic gameplay: bowler to batter During normal play, thirteen players and two umpires are on the field. Two of the players are batters and the rest are all eleven members of the fielding team. The other nine players in the batting team are off the field in the pavilion. The image with overlay below shows what is happening when a ball is being bowled and which of the personnel are on or close to the pitch. In the photo, the two batters (3 & 8; wearing yellow) have taken position at each end of the pitch (6). Three members of the fielding