Within softball there are two variations of the sport, slow-pitch and fast-pitch softball. Softball is a direct descendent of baseball and follows similar rules, however have some obvious differences. First off, the ball used in softball measures eleven to twelve inches in circumference and is much larger than a baseball. Secondly, in baseball there are nine players on the field where in softball there are ten including an extra outfielder. Since the ball used in softball is bigger than the ball used in baseball, the gloves, also known as mitts are also larger. All defensive players must wear fielding gloves which are made of leather or similar material. Softball gloves have webbing between the thumb and the forefinger so that a solid grip is maintained. Compared to the other defensive players, the first baseman and the catcher may wear mitts that are slightly larger and have extra padding with no finger holes. All the other players may have any color gloves except for the pitcher, his glove cannot be white or gray as it may confuse the batter. Quality of the gloves usually depends on the thickness of the leather and how well the ball comes in and out of the pocket of the glove. The difference between an open web glove and a close web glove is that an open web glove traps the ball better while the other tends to get the ball out of the pocket much quicker. Therefore players select their gloves depending on the positions that they play. 1st and 3rd basemen prefer open web gloves while middle infielders choose closed web gloves. Pitchers usually use close web gloves so that they can hide the ball from the batter. Conventional gloves compared to closed back gloves come down to the personal preference of the player. Conventional gloves are lighter and fit tighter on the wrist while closed back gloves have Velcro straps that are adjustable according to the player's wrist.