What is Zone Rating? Definition and Example
Zone Rating (ZR) is a defensive metric that measures the percentage of balls hit into a fielder's defined zone that he successfully converts into outs.
What is Zone Rating?
Zone Rating (ZR) is a defensive statistic that evaluates a fielder's range and reliability by dividing the field into defined zones and measuring what percentage of balls hit into a fielder's zone result in an out. Unlike traditional fielding percentage, which only measures plays a fielder attempts, Zone Rating accounts for balls a fielder should have reached but didn't. A shortstop with a Zone Rating of .850 converts 85% of balls hit into his zone into outs. The metric was developed by John Dewan in the late 1980s and became a standard public defensive metric before Statcast's Outs Above Average replaced it as the modern gold standard.
How is Zone Rating Calculated?
Zone Rating assigns every batted ball to one of 78 zones on the field. Each defensive position is assigned responsibility for specific zones based on typical positioning. The formula is:
ZR = (Plays Made) / (Total Balls Hit into Zone)
Plays made include outs, assists, and errors on balls in the fielder's zone. Balls hit outside a fielder's zone that he converts into outs are tracked separately as "out-of-zone plays" and do not count in the numerator or denominator. The league-average ZR varies by position: shortstops typically post .840–.860, while first basemen post .900–.930 because they receive more routine throws and grounders.
Worked Example
In 2010, shortstop Troy Tulowitzki posted a Zone Rating of .873, meaning he converted 87.3% of balls hit into his zone into outs. That ranked among the best in baseball that season. By comparison, the league-average shortstop posted roughly .850. Over 400 balls hit into his zone, Tulowitzki made 349 plays while the average shortstop would have made 340. That nine-play difference translated to roughly 7 runs saved, a meaningful defensive edge. Modern Statcast data shows similar range for elite shortstops: Dansby Swanson posted an Outs Above Average of +21 in 2022, which converts to roughly 16–18 runs saved above average.
Why Zone Rating Matters
Zone Rating matters because it captures the two core components of defense: range and reliability. Fielding percentage punishes errors but ignores balls never reached. A slow-footed third baseman who fields every ball he reaches cleanly posts a .980 fielding percentage while allowing dozens of extra hits through the gap. Zone Rating exposes that gap by penalizing balls not reached. Front offices used ZR heavily in the 2000s and 2010s to evaluate shortstops, center fielders, and third basemen — positions where range drives defensive value. Fantasy players in leagues that track defensive stats use ZR to identify undervalued players who save runs but don't hit for power.
Limitations and Common Misconceptions
Zone Rating has significant limitations. It relies on a fixed zone grid that doesn't adjust for shifts, handedness of batters, or ballpark dimensions. It doesn't account for the difficulty of plays within a zone — a slow roller and a screaming line drive to the same zone count equally. It also fails to credit outfielders for throwing out runners, a skill captured by other metrics. ZR is often confused with fielding percentage, but they measure different things: fielding percentage measures errors on plays attempted, while ZR measures success rate on all balls hit into a defined area. ZR is also position-dependent — comparing a first baseman's ZR to a shortstop's ZR is meaningless because their zones differ dramatically. Modern Statcast metrics like Outs Above Average and Catch Probability have largely superseded ZR because they use actual player positioning and ball-tracking data rather than static zones.
Related Terms
In Legends Deck:
Legends Deck uses Zone Rating as a secondary defensive input when rating cards for infielders and outfielders. Players with high ZR receive boosts to their defensive card ratings, particularly for range-related attributes. A card with a .870 ZR at shortstop grades out higher on the 20–80 scale for range than a card with a .830 ZR, even if both post identical fielding percentages. This makes ZR a useful tiebreaker when comparing similar players on the auction block.