Active voice vs. passive voice...remember that? "Tom threw the ball." The verb "threw" is active voice, because "Tom" acted - did the throwing. "The ball was thrown." Now the verb is passive voice, since the subject of the sentence, the ball, was acted upon (it was thrown, poor thing).
Anyhow, anyone who has ever taken a short course on creative writing knows we’re supposed to use active verbs! Don’t say "the balls were under-inflated." Say, "Tom under-inflated the balls." Don’t say, "the game was won by cheating." Say, "Tom won the game by cheating."