We’ll continue to look at the subject through a slightly different lens this week: stats we track known as "Good Baserunning Plays" and "Bad Baserunning Plays."

These plays are based on review by our Video Scouts who use specific criteria in determining good and bad baserunning. The most common Good Baserunning Play is "Baserunner Takes an Extra Base." These are bases gained that are deemed to be ones that most players wouldn’t gain. Here’s an example from earlier this season, a double by Fernando Tatis Jr.

Another example of Good Baserunning would be Amed Rosario’s nifty tag of home plate on Tuesday night, in which he just avoided the catcher’s reach. Rosario gets credit for "Avoiding the Tag."

Bad Baserunning Examples include "Failing to Advance (Tag Out)" which occurs when a batter or runner gets overly aggressive and is thrown out (for example, Paul Goldschmidt on this play), and also things like "Doubled Off" for being the baserunner on a line drive or fly ball double play (as Brett Gardner was here).

Cubs catcher Willson Contreras has been MLB’s most adventurous baserunner in 2021. He has an MLB-high 7 Good Baserunning Plays and is tied with Gio Urshela of the Yankees and Adolís Garcia of the Rangers for the MLB lead with 6 Bad Baserunning Plays.

Contreras’ having 7 Good Baserunning Plays is notable given that he had none in 2019 or 2020. Among his highlights was this hustle double against the Mets, advancing to second on a wild pitch that stayed in front of the catcher against the Indians, and scoring on the famous Javier Báez retreat to home plate against the Pirates (for which Báez received a Good Baserunning Play for "Keeping the Play Alive").

Here are the leaders in Good Baserunning Plays in 2021.

Most Good Baserunning Plays (GBRs) – 2021 Season

Ronald Acuña Jr. ranks second in Good Baserunning Plays with 6, but unlike Contreras, he has only 1 Bad Baserunning Play this season. Acuña Jr. seems to have learned from the early part of his career. In his first three seasons, he had 3 Good Baserunning Plays and 16 Bad Baserunning Plays.

Báez leads MLB in Good Baserunning Plays over the last three seasons with 16, one more than Bryce Harper. Contreras’ 19 Bad Baserunning Plays are the most in MLB in that span.

Here are the leaders in Good Baserunning Plays since 2019.

Most Good Baserunning Plays (GBRs) – Since 2019

Given the presence of Báez and Contreras, it’s not surprising that the Cubs lead the majors with 19 Good Baserunning plays in 2021. The Dodgers and Braves are tied for second with 14. The Yankees and Athletics are tied for the most Bad Baserunning Plays with 27.