Base-Out Wins Added Calculator

Base-Out Wins Added (BOWA) distills every plate appearance into a single number that reflects its impact on winning.

By comparing run expectancy before and after an event, the metric shows exactly how much value a player contributes in real time.

Use the calculator below to plug in the base-out state you started with and the one you finished with, then see the precise swing in expected wins that resulted.

This metric not only highlights a player’s contributions during critical moments but also provides insights into how individual performances translate into team success.

Understanding baseout wins saved explained allows fans and analysts alike to appreciate the nuances of situational baseball and how specific actions can alter the trajectory of a game.

By analyzing this data, teams can make informed decisions about player development and in-game strategy to maximize their chances of winning.

Base-Out Wins Added FAQ

What is Base-Out Wins Added?

Base-Out Wins Added, or BOWA, measures the change in expected team wins from the start of a plate appearance to its end, given the base and out situation.

Where do the run expectancy numbers come from?

Run expectancy tables are built from historical play by play data that average the runs scored from any identical base-out state until the inning ends.

How is BOWA different from WPA?

Win Probability Added uses inning, score, and home field context, while BOWA isolates only the shift in base-out run expectancy, making it context neutral.

Can pitchers accumulate negative BOWA?

Yes.

If a pitcher allows a hit that raises the opponent’s run expectancy, his contribution will be negative, reflecting value surrendered.

Why round to three decimals?

The three decimal format balances readability with precision, preventing minor noise from overshadowing meaningful changes in expected wins.