Just curious, what specifically is the person behind the plate doing? Ive been to a few college games and noticed a person tracking info. They generally are tracking speed with a gun, but how do they quantify the pitch. Are they evaluating movement and location including speed?
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Typically one person is charting the type and location of the pitch and someone else is working the gun. The folks behind the catcher are reading the movement (or lack thereof) and the location. They may also be recording the result, or that could be a 3rd person. Since they do not know what was called they are not biased by the intent of the called pitch. This data is then reconciled with the data from the dugout. You then have a pretty accurate assessment of what was called and the result. In addition to charting pitches video may be collected on every swing, from 2 - 3 locations.
This is what I have seen in the SEC, PAC 12, etc. Obviously what happens in the lower levels is another matter. But if you want accurate, actionable information you need at least 2 people. One recording the intent, the other recording the result. Interpreted correctly this will provide significant insights into pitching performance.