Pitcher was a righty.
Berkman is a switch hitter, batting lefty.
Speedy Taveras on 1st.
So you have 2nd baseman cheated towards the bag at 2nd base to cover for a steal, and double play depth anyway. And you have the first baseman covering the runner at first, so you have a gaping hole on the right side of your infield vs. a good left handed hitter.
Two pitchouts. Count is 2-0.
So you have righty pitcher, vs. lefty hitter with power to the gaps and a gaping 4-hole. Double scores Taveras from first. And a ground ball to the 4hole may be run rabbit run for Taveras. Ground ball to the right side, and Taveras goes to 3rd base, with 1 out, so a sacfly scores him.
Ensberg on deck. Righty/righty matchup and a fresh count. Coupled with the potential fictional scouting report on Ensberg rolling over breaking balls low in the zone. Coupled with a smaller hole on the left side of the infield because the 3rd baseman can cheat over. [(He's not playing the line (no doubles) so anything hit down the line will score him anyway, so he's cheating towards the 6 hole.)]
You also have Berkman less likely to break up a double play at 2nd, Taveras may be able to get there with his speed and disrupt the turn.
Picture is getting a bit clearer. But I still dont think I would of done it. Id cheat my RF a bit to the left to protect from a 4 hole groundball and bring him in a bit to protect from Taveras advancing to 3rd on a 4 hole basehit. I'd unintentionally, intentionally walk Berkman, and throw him all breaking balls, because hes sitting dead red.