The shift should be your basic defense. Data has proven that it is much better to cover 100% of ¾ of the field than it is to cover ¾ of 100% of the field. Think about it, why would you purposely cover an area with the same man power that has a 10% probability versus an area that has a 40% chance of probability? Does that make sense? Of course not. By covering that low percentage area, I am taking away my ability to cover the higher probability area. No reason to cover the opposite line if a hitter hasn’t shown the ability to hit it there, right?
Now, here is where the controversy lies. What if you have no data on the hitter? MLB clubs have a plethora of data and can justify positioning but what about college/high school/travel ball teams that don’t have access to that kind of data? Well, what makes you sure your straight up positioning is any better in those situations? This is a good argument for shifting based on the count. Typically, hitters will be early and more aggressive when they are ahead of the count. In this scenario, why not shift your infielders, your outfielders or both to pull side and see what happens. I bet you will make more plays. Conversely, when the hitter is behind in the count, they tend to stay up the middle more. Why not bunch your defense to the middle and leave the lines alone. By taking away the middle 75% of the field, you will find your defense making more plays and getting more outs. Again, the percentages of with you when you take away 100% of ¾ of the field.