Which pitch can depend on the umpire too. My son is a LHP who throws mostly a 2-seam fastball. It moves down and away from right handed pitchers. He is very adept at cutting the front edge off the plate for strikes. Unfortunately, the umps aren't always as adept as seeing that pitch as a strike. He had to learn to throw the 4-seam for a strike in the same location without the sink to get the strike called. A ball thrown with late movement is better than a faster, flatter pitch. Batters have a tougher time adjusting to the pitch.