Exploring advanced stats - DRS

Judging defensive prowess in baseball is a tricky business. On the offensive and pitching sides of the ball, the eye test is normally pretty reliable. Simplified, a ball hit far is a well hit ball. A pitch thrown hard is a well thrown pitch. But defensively, things get a little convoluted.

Traditional judgment of a player’s defense starts with fielding percentage, the proportion of times the fielder properly handles a thrown or batted ball. This typically aligns with the eye test. A cleanly fielded grounder is good, a booted ball is bad. And this makes sense intuitively - when assembling a team, you want the defenders who make the fewest mistakes. While this logic is sound - Todd Helton’s career .996 fielding percentage makes him well worthy of his multiple Gold Gloves and reputation as defensive backstop - the reliance on errors makes it subjective.

First, what is and is not an error is decided by the official scorer for each game. Each scorer is human, so each scorer is different. Add in each scorer having a rooting bias, and it’s easy to see how multiple errors could go either way over the course of the season.

The next problem with fielding percentage is that not every player’s range is the same. A 35-year old Charlie Blackmon cannot cover as much ground in the outfield as a 28-year old Raimel Tapia. So if Tapia gets to a fly ball and bobbles it, while Blackmon isn’t able to get to the same ball and it drops in front of him, is it fair that Tapia is charged with an error while Blackmon does not? No, the outcomes of both plays are the same. This is where the metric Defensive Runs Saved (DRS) comes in handy.

Developed by Baseball Info Solutions, DRS is just like what it sounds: a measure of how many plays a specific fielder made compared to the average fielder at that position. This is done by comparing every ball hit similarly at each hitting vector, then adding or subtracting points from players when they make plays that are above average, or fail to make those that are below average. That number is then converted into a run value - The Fielding Bible has a more in depth explanation of this here.

In 2021, the Rockies list for DRS was highlighted by Ryan McMahon.

The full list for the team is here. Not only did his 22 DRS lead the Rockies (13 DRS at 3B, 9 at 2B), but it led the league. Not that that did enough to convince Rawlings that McMahon was worthy of the Gold Glove, however. The eye test is still hard to disagree with, just ask Derek Jeter.

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Meet Emily Glass, the Rockies’ first female scout | The Denver Post ($)

One of the many new faces in the Rockies front office for the upcoming season, Emily Glass looks to be among the most qualified. Her experience includes stops with MLB International in the Dominican Republic, as the Miami Marlins’ education coordinator, and even as a little league coach in Japan (highlighted as the “toughest thing she’s ever done”). Glass will have her work cut out for her rebuilding the Rockies farm system, between her work as scouting operations administrator and field work in the Colorado and Wyoming regions.

Drellich and Rosenthal: No reason to believe MLB season will start on time | The Athletic ($)

Yesterday, Super Bowl Sunday, marked day 74 of the MLB lockout. And no end is still in sight. In their latest proposal to the players, “...the league moved a few feet when the players are still asking for miles.” The small concessions offered by both sides thus far are moving the two groups closer together, but not remotely close to a rate that would imply that they’ll be on the same page with time enough to meet the current date scheduled for Opening Day.

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