Everything stays closed — his hips and his shoulders specifically — until the very last second before unloading on the ball, something you can see in the clip below. He lets the ball travel deep into his hitting zone and he finishes with force, swinging through the ball and not cutting his swing short. I pause the clip at the frame where he first decides to commit to the pitch. Note how deep the ball has traveled before he commits to swinging. When you wait as late as he does, you get a better idea of the pitch type and location.