Too often pitchers get ahead in the count and give up a hit or walk. What causes this failure to finish? You can cite many contributing factors, but often it is because the pitcher missed the most important pitch.
The most important pitch may not be the one that allows the hit or walk, but the one just before that, which was designed to set up the strikeout. Remember, the batter is filled with adrenalin when she gets two strikes and it is tougher to get the ball past her. A good hitter will shorten her swing and seek contact. You need to stack the odds by getting her off-balance. Every pitch must serve a purpose to achieve this.
If the coach or catcher is good at calling pitches, they know exactly which pitch will get the K. They set it up with something designed draw the hitter’s attention away from the pitch they plan to use to close the door. At lower levels it might be as simple as throwing a couple of pitches barely off the plate to get the batter leaning forward just a bit so they can follow with heat on the inside corner. So which was the most important pitch? It is the one just off the outside corner. It is a lot easier to finish the batter with the inside pitch if she was nervous about the outside corner. But, if you miss too far outside, the batter regains confidence and expects the pitcher to bring it to a different place. The inside pitch loses effectiveness because it was not set up properly.
As the pitcher matures, we use a different technique. If the pitcher has a great inside riseball, perhaps she gets two strikes immediately. I want to finish that batter with an inside riseball, but we have two different ways to get there. I can throw the pitch just a little higher so the batter has no chance to hit it, or I can go away from her with a couple of dropballs or curves so her eyes adjust to the new trajectory. If I chose to go higher with the riseball and she didn’t bite, this is the point where we go to the outside for a pitch or two, but I still stay slightly off the plate. The purpose is the same in both cases; to get her accustomed to a different movement and location so that the riseball is fresh again and we can finish the at-bat with a K. However, if you missed those “waste” pitches too far, she knows where you have to go with the next pitch. Things just got tougher.
Two things are extremely frustrating to the person calling the pitches. The first is a failure to execute the “set-up pitches” well. The second is for the batter to be primed for a K but the pitcher misses the final pitch badly. Now we have fewer options and have to “get more plate”. As a pitcher progresses to higher levels she learns that every pitch must serve a purpose. Waste pitches can be even more important than strikes. Sometimes they even get a “chase response” from the batter, or a favorable call from the umpire, and we never have to throw the strikeout pitch.
There are hundreds of variables and strategies. The one constant is execution. It is not a perfect world, but if you focus carefully, knowing the exact purpose of each pitch, you will be much more successful. The most important pitch may not be the final pitch, but the one that put the pressure on a batter and confused her so badly that the final pitch didn’t have to be perfect to get a perfect result.