Pitchers with best, worst defensive help

Scott Spratt from Baseball Info Solutions is filling in for Eric Karabell, who is on vacation this week.

Mark Buehrle continued his excellent start to the season Thursday with seven innings of two-run ball to beat Jon Lester and the Boston Red Sox. That actually raised his ERA to 2.16, but that is still second-best in the AL behind only Sonny Gray of the Oakland Athletics.

Tim Hudson eased back into things with only three innings of work in Colorado last night after a hip injury forced him to skip a start. His fantasy owners can breathe easy now that he’s back and escaped Coors without much damage. Hudson has still never won in Colorado, but he allowed just one run in his three innings and continues to enjoy a 2.13 ERA.

Buehrle and Hudson are on the short list of fantasy MVPs so far in 2014. Both players have been in the majors since the start of the century, so seeing them on pace to comfortably set career bests in ERA is certainly a surprise. However, Buehrle and Hudson have something else in common, and it’s the biggest reason their early-season success is unlikely to continue.

Baseball Info Solutions measures how frequently defenders make plays on balls relative to the average defender at their position in a statistic called Plus/Minus. So if a shortstop has a Plus/Minus of five, it means we estimate he has made five extra plays compared to an average shortstop that saw a similar collection of batted balls in terms of their locations and velocities. Plus/Minus is a foundational component of Defensive Runs Saved (DRS), which we typically cite for individual fielders. However, we can also measure how many runs all fielders on a team have saved because of Plus/Minus with a specific pitcher on the mound.

Even two months into the season, the pitchers with the best and worst defensive help can differ by 20 to 30 runs of defensive support. And eight runs saved are enough to reduce a pitcher’s ERA by a full run when he has thrown only 70 innings. Some teams are better than others defensively, and pitchers with excellent defensive support from teams that are exceptional defensively can likely expect that trend to continue. However, some pitchers have enjoyed defensive help uncharacteristic of their team’s overall defensive numbers, and others have been victimized by poor defense from teams that have otherwise performed well defensively. Those pitchers could be in for dramatic changes in their ERA the rest of the season.

Pitchers with best defensive support, This season