One of the least understood and incorrectly executed movements is  the Crow-Hop. This movement used by outfielders correctly will improve  throwing accuracy and strength. So what is a Crow-Hop? Basically, it is a  movement the player executes to provide balance and throwing momentum  after the catch. The catch can be on ground balls or fly balls - but the  player must properly use the Crow-Hop to give him the best chance of  making good throws. Balance is the goal and the key to good outfield  play.
The Crow-Hop
This next sequence is done in one fluid  motion. After catching the ground ball, the outfielder should push off  the front knee and replace the front foot with the back foot. The best  way to do this is to elevate off the ground, lift the back knee first,  then the front knee, and put the back foot down approximately where the  front foot was. When done correctly, the back-knee/front-knee lifts and  back-foot/front-foot exchange happens quickly. While elevating and  replacing, the player should also turn his torso and hips so that his  glove shoulder is pointing toward the target. This motion is called the  Crow-Hop.
The Crow-Hop is a movement that gets the player best  positioned to throw the ball. The outfielder is creating balance,  aligning shoulders to the target, and loading up his throwing (back) leg  for the throw. Loading the back (throwing-side) leg is a term used to  describe the beginning of the throwing motion. Simply put, it means most  of the players weight is on his back leg. Most means more than 50  percent and less than 100 percent. Some instructors like to pinpoint the  exact percentage, but my experience with thousands of ballplayers tells  me it is a little different for each player. The average weight  distribution is about 80-20 back leg to front leg.
Like most  sports including baseball, a player must move in one direction to move  better to the opposite direction. Both hitters and pitchers do this as  well. Its a mechanism for balance and bodily energy. Some players  exaggerate the crow-hop by lifting their knees very high, almost like a  marching band. Other players drag their back leg in to a bad, or  "short", position - and the back leg never gets completely under the  body. Neither of these methods is correct.
The proper technique is  to lift the knee high enough so the players back leg supports the  body. This creates balance - and good throws. When outfielders get  really good at the Crow-Hop technique it looks seamless and smooth.
Caution: Sliding, Cha-Cha, and Gliding
Many  players, me included in my youth, try to execute the crow-hop without  clearly replacing one foot with the other. They just slide the back  foot, leaving it short of replacing the front (glove-side) foot. First  hand experience shows that this results in bad balance and poor throws.  Once I learned to lift my knees and position my throwing leg underneath  my body, my balance and throws were consistently good. Figure 2-6  illustrates the incorrect Sliding Crow-Hop. You can see that the  outfielder has not loaded his back leg, is overstretched and  off-balance. This throw is highly likely to be a poor one.
A  common situation of the Sliding Crow-Hop happens after his back leg has  slid short of full balance. The players brain tells him he is  off-balance and he tries to correct it by quickly re-positioning his  back (throwing-side) leg. His front leg is still in the air while his  back leg is pumping up and down. This makes him look like he is on a  pogo stick. He pumps his back leg two or three times to try to get  balanced - and all the while his momentum is carrying him forward so  that he rarely gets fully balanced.
Another incorrect variation of  the crow-hop is what I call the Babe Ruth Cha-Cha. The Babe would move  up in the batters box to swing at a curve ball before it curved. He did  this by moving his back foot behind his front, then striding to hit the  ball. A lot of slowpitch softball hitters do this too. Again, you see  that the player is off-balance. He is also moving parallel to the  target, taking his momentum off-target. Arm strain and bad throws surely  will result. Many players use the Cha-Cha move to turn their upper  bodies to throw. While the move does align the players shoulders to the  target, it also reduces balance and momentum.
The Gliding  Crow-Hop looks like a mid-air scissor kick, as if a ballet dancer were  fielding the ball. The players knees do not lift; instead he leaps up,  brings both straight legs together, then strides out with his front  (glove-side) leg while his throwing leg hits the ground. To most  untrained observers, this looks pretty good. But gliding has very high  odds of getting the player off-balance. Most times, the players  momentum is moving so fast that he does not allow himself to properly  load his back leg for the throw. The Gliding Crow-Hop also never allows  the outfielders back leg to get fully loaded. He is so off-balance that  many times he falls forward to the ground after the throw.
I hope  this helps players and coaches know the correct and often-used  incorrect ways to use the Crow-Hop in the outfield. You will be amazed  at the improvement in your fielding and throwing by properly executing  this critical movement. Thanks for reading!