The Babylonian and Aramaic versions of the Bisitun inscription give precise enumerations of enemies killed and captured by the armies of Darius I in 522-521 BC. But the figures are absent from Bisitun's other versions, and their accuracy and historical value remain in question. This study reviews their textual reliability and modern reconstructions and argues that they do not reflect accurate counts of battlefield dead or prisoners. It proposes that the Babylonian text offered more space for additional material than its Elamite or Persian counterparts and that its casualty figures enhanced Darius' military narrative by quantifying his superiority to subordinates: enemy losses are highest when the King commands in person, less for generals in separate commands, and lowest for Darius' non-Persian lieutenants. Explanations are considered for a possible exception, the victory of the satrap Dadaršiš in Margiana.