Walks Allowed measures the total number of times a pitcher allowed a hitter to reach base on balls by throwing four balls before striking a hitter out or having that hitter reach base by way of a hit.
Also referred to as "Base on Balls Allowed."
More about Walks Allowed Leaders
Pitching total walks allowed leaders give up the most number of walks over the course of the season. Those who give up the most number of walks are also likely to be among the league leaders in strikeouts. The leaders in this category are not necessarily bad pitchers but face enough batters to have an opportunity to walk a significant number of batters. In recent years allowing 80 or more walks in a season (which works out to about 2.5 walks per start if a pitcher makes nearly every possible start over the course of a season given a five-man rotation), whereas 20 years ago allowing walks in triple digits was required to be a league “leader”.