The Training Room WHAT CAUSES A KNUCKLEBALL TO "KNUCKLE" Play Episode Pause Episode Mute/Unmute Episode Rewind 10 Seconds 1x Fast Forward 30 seconds 00:00 / 5:26 Subscribe Share RSS Feed Share Link Embed http://thetrainingroom.tv/wp-content/uploads/2021/07/TrainingRoom_knuckleball.mp3Podcast: Play in new window | Download Find out the real truth about what causes a knuckleball to behave in its erratic, unpredictable motion. In other words, to “knuckle”!!