7.1 Background

• “Historically, scouts and coaches insisted that certain catchers had the ability to “frame” pitches for umpires. The idea was that by holding the glove relatively still, you could trick the umpire into calling a pitch a strike even if it was technically outside of the strike zone”
• “Part of the problem was that until the mid-2000s, pitch-level data was hard to come by. With the advent of PITCHf/x, more sophisticated modeling techniques became viable on these more granular data.”