Changing how baseball defense is evaluated today

You’ve seen it with your own eyes, every single game you watched live or on a screen: Defensive shifting is up more than 350% since 2014, and that was after a 500% increase from four years before that.

As defense changes, our ability to make better evaluations of players and teams also grows. In The Fielding Bible,Volume V, Sports Info Solutions (the producer of the annual bestseller The Bill James Handbook) introduces the PART system for analyzing infielder defensive performance. PART (Positioning, Air Balls, Range, Throwing) allows us to separate positioning from performance. We can now transition from “How much credit should a player get for making that play?” to “How much credit should a player get for making that play given where he was positioned?”

We’re now able to evaluate all infield plays, not just ones involving an unshifted defense. The result, we believe, is a more accurate overall depiction of defensive performance.

• Defensive Runs Saved: A comprehensive explanation of our new methodology for analyzing infielders. Which players were most impacted?
• Team Analysis: An analysis of the top defensive stories of every MLB team with never-before-seen data. Plus, a positional breakdown of each team’s Defensive Runs Saved.
• Player Interviews: Standout baseball fielders Nick Ahmed and Austin Hedges on what goes into playing the way they do; Kevin Pillar on making amazing catches; top prospect Ke’Bryan Hayes on what it’s like to learn third base; and Hall-of-Famer Ozzie Smith on what defensive excellence is all about.
• Top Player Breakdowns: How do Matt Chapman and Nolan Arenado compare at the hot corner? How did Paul DeJong emerge as one of the top-performing defensive shortstops in MLB? Plus, who made the Fielding Bible All-Decade Team?
• Unique New Studies: How do park factors and player aging curves impact defensive performance? Which teams position their infielders most effectively? How effective is playing the infield in?
• Career Stats: Defensive numbers for everyone who played in MLB last season, including Defensive Runs Saved, Good Fielding Plays and Defensive Misplays, Outfield Arm and Infield Arm Runs Saved, Strike Zone Runs Saved (our pitch framing stat), and much more.

Authors

John Dewan, author of Volumes I and II and co-author of Volumes III and IV, has consistently broken new ground in statistical sports analysis, with defense as his specialty, first as one of the founders and former CEO of STATS Inc. and now as the owner and CEO of Sports Info Solutions (SIS).

Mark Simon, senior research analyst at SIS, former head researcher on ESPN’s Baseball Tonight and author of the book The Yankees Index, has written about and researched baseball for more than 20 years.

Brian Reiff, research analyst at SIS since 2016, is a leader of its Research and Development team, producing meaningful and insightful analysis for both baseball and football.