There are two different game scenarios for a passed ball situation: (1) a lone runner on first or second, nd (2) a runner on 3rd base. Both use the same technique for going to the ball and discarding the mask. The difference is in what the catcher does as he approaches the ball.
The Approach. Catchers should always turn to their left as they head back to the ball as shown in the below illustration. This means that the catcher will approach the ball from the right side regardless of where the ball is located.
Getting The Ball. As the catcher gets close to the ball (having already discarded his mask), he should drop to his knees and slide to the ball. The catcher is now in a better position to make a throw to the plate or a base and this technique permits him to attack more aggressively especially if the ball is up against the backstop. A catcher's shinguards and chest protector will take the impact if there is one rather than his body. It also lets the catcher approach the ball without slowing up as he nears the backstop, which save precious seconds.
A Runner On First or Second Base. Because this situation will seldom result in a play at home, the catcher should concentrate on the lone runner. As he gets to the ball he should rake it into his throwing hand with his glove and NOT grasp it with the glove. The catcher will then popup into his throwing ready position and quickly determine if there is a play to be made. If so, then the catcher should make his regular throw to second or third base in order to nab the runner.
A Runner On Third Base. As the catcher gets to the ball he should rake it into his throwing hand with his glove and NOT grasp it with the glove. Instead of poppping-up, the catcher remains on his right knee and lifts his left leg up so that his left foot is flat to the ground with his thigh parallel to the ground. The catcher then makes a hard crisp throw to the pitcher's glove. It is important that the catcher throw to the GLOVE even if the pitcher has his glove too high for a good tag. Too often a catcher will make the hard throw (from twenty feet away) to where the tag should be made and the ball just sails past the pitcher's knees because he cannot react quickly enough to the throw. It is far better to hit a chest high glove and miss the tag than let an errant ball travel through the infield. Practice between catchers and pitchers with both getting into the proper position (catcher on his right knee and the pitcher down low with his glove 18" off the plate) will greatly reduce errors and increase tags at home on passed balls and wild pitches.
Pre-Game Routine. Catchers should have a pre-game routine, especially on away games. They should practice sliding in a few locations behind the plate and up against the backstop. They should walk along the grass or dirt line along the backstop looking for debris or things like sprinkler heads. They should search for anything that will interfere with their game play. This also means looking at the bottom of the fence for holes and poorly maintained fencing that may pose a danger to them. A few moments spent in pre-game assessing the territory (sliding around and examining) will make a big difference during the game.
Dave Weaver, [ email@example.com ]