What Does BB Mean in Baseball? Base on Balls (Walk) Explained
BB in baseball stands for base on balls — universally called a walk. When a batter takes four pitches outside the strike zone in one plate appearance, he is awarded first base. A walk is not a hit and not an at-bat, but it does raise on-base percentage.
What Does BB Mean in Baseball?
BB stands for base on balls, the formal name for what everyone calls a walk. A batter draws a walk when he takes four pitches outside the strike zone during a single plate appearance before he makes an out or puts the ball in play; the umpire awards him first base automatically. The abbreviation is "BB" rather than "W" because "W" was already taken by the pitcher's win, so the box score borrowed "base on balls." On a hitter's line BB is the walk total; on a pitcher's line BB is the number of walks he has *issued*, which counts against him.
How Does a Batter Earn a BB?
A batter earns a base on balls by accumulating four "balls" — pitches the home-plate umpire judges to be outside the strike zone that the batter does not swing at. The count starts at 0-0, and the fourth ball ends the plate appearance with the batter taking first base. There are two flavors: an ordinary (unintentional) walk drawn pitch by pitch, and an intentional walk (IBB), where the defense deliberately puts the batter on first — since 2017 a manager can signal an IBB from the dugout without throwing the four pitches. A hit-by-pitch also awards first base but is scored separately as HBP, not a walk.
Does a Walk Count as an At-Bat or a Hit?
No on both counts — and that distinction is the whole reason walks are valuable. A base on balls is not a hit and not an official at-bat, so it has zero effect on batting average (it neither helps nor hurts the AVG numerator or denominator). But a walk *does* count as a plate appearance and *does* count as a time on base, so it directly raises on-base percentage. This is why a patient hitter with a modest batting average can still be enormously productive: every walk is a free baserunner that AVG completely ignores but OBP rewards. A hitter batting .250 who walks a lot can easily out-produce a .280 hitter who never does.
Worked Example
Bases empty, full count at 3-2. The pitcher misses just off the outside corner; the batter, who never offered at a pitch out of the zone, flips his bat toward the dugout and trots to first — BB. The official scorer logs the plate appearance as a walk: no at-bat, no hit, one time on base. The hitter's batting average is unchanged, but his on-base percentage ticks up, and the leadoff runner is now a stolen-base threat. Had he chased that 3-2 pitch and grounded out, the same plate appearance would have become a hitless at-bat that dragged his average down — the difference between a walk and an out is enormous even though neither produces a hit.
Why Walks Matter
Walks are the cleanest measure of plate discipline and a huge driver of run scoring, because the single most important thing a hitter can do is avoid making an out — and a walk does exactly that without even putting the ball in play. The skill behind walks is *not chasing*: hitters who lay off pitches outside the zone force pitchers into the strike zone or into ball four. That is why walk rate and chase rate are tracked closely as leading indicators of a hitter's underlying quality, often before the batting average catches up. A rising walk rate is one of the earliest signs a young hitter is figuring out the strike zone.
In Legends Deck
Legends Deck treats walks as a core on-base skill rather than an afterthought. A card's tendency to draw a base on balls is tied to its walk rate and chase rate inputs — disciplined cards that lay off pitches outside the zone work deep counts and reach base via the walk in-sim, feeding directly into their on-base percentage. Because the engine scores reaching base the same whether it comes from a single or a walk, high-discipline profiles hold value even when their power is average. Explore the full set of Statcast-driven plate-discipline inputs on the leaderboards hub.