Depends on how they look at the "data". I.E. Lets say the evidence establishes that Corey Seeger facing a left handed pitcher who 80% of the time throws curveballs on the first pitch and Seeger "normally" is a first pitch swinger and "tends" to hit the ball to the third base side of the infield they will then place and extra infielder on that side. If the evidence shows the same pitcher on a 3-2 count will more often than not throw his fastball and Seeger tends to hit left handed fastballs to the right side of the infield they will on such a count overload the right side of the infield.
Without the computer one would be guessing on these tendencies. Some of the young people you may have seen-but didn't recognize-in the champagne dredged post game celebration-were likely data engineers who make lots of $$ in the Dodger organization developing programs to determine tendencies of various players.
