The goal of every defensive player is to get behind every ball.  This begins with a mental readiness and determination as well as the ready position.  As a general rule, the closer your position is to home plate, the closer your glove is to the ground, and the farther apart your feet are in the ready position.
  In the ready position, the athlete wants to be able to move in the direction of the ball without any wasted movements.  It is recommended to have the glove positioned in an efficient manner.  Therefore, the glove should NOT be on the ground in the ready position, because we don't move to a ball with the glove on the ground.  The elbows should be bent close to a 90 degree angle, or L-shaped, which is again an appropriate form of motion.  For 1st and 3rd base positions, the elbows are positioned outside the knees.  The farther your position is from home plate, the more range you need to have.  Therefore, you are positioned with less bending in the knees in order to explode in the direction of the hit more efficiently.