Team walks allowed per nine innings is the number of walks (intentional and unintentional) a pitching staff allows over a typical nine inning game.
Also referred to as "Base on Balls Per Nine Innings."
More about Team Walks Allowed Per Nine Innings
Unlike hits per nine innings, which leaves some chance in the air due to a team's defense, a pitching staff has nearly entire control over the number of walks it allows (with the exception of managers ordering intentional walks). Intentional walks can actually be greater in the National League, despite there being less scoring, due to players being walked so as to face a weak-hitting pitcher. That being said, most team leaders in walks allowed per nine innings still come from National League pitching staffs.