essentially, the direction is where the dot is in relation to the center. The further out the dot is from the center, the more rotational speed it has (or magnitude). Matched up with the horizontal charts (where there is some guesswork in determining which dots are which, but it is usually obvious), you can see that the two seamer has 3 or 4 inches more of horizontal movement than the four seamer. There is probably one that should be classified as a four seamer and one that should be classified as a two seamer. Looking at the conglomerate of the charts together, you can basically circle certain clusters of dots that are probably the same pitches. Again, since gameday can't read the players finger positioning, these are mainly super educated guesses by a computer system that compares to a historic normalized database.
The guys on TV are just guessing. I quit listening to them and just pay attention to speed and break. I also look for pitches that break late and violently. Zimmermann threw a couple yesterday that were real ball breakers.
