Christenson (2007: note 244, pages 105-106) rightly points out the difficulty of documenting this object in alphabetic sources. He writes: "Unfortunately b'ate does not appear in any early colonial dictionaries, perhaps because the ballgame ceased to be played soon after the Spanish conquest. Thus the names for the equipment used in the game fell out of usage. From the description found later in the Popol Vuh text, the ball bounces off of this article in the process of playing the game. I have chosen to translate the word as 'yoke,' a well-known article of ballgame equipment throughout Precolumbian Mesoamerica. It is a U-shaped apparatus worn about the hips and used for striking the ball to keep it in play. Yokes were probably made of wood, although intricately carved stone replicas have been found in many parts of ancient Mesoamerica, particularly along the Gulf Coast of Veracruz."
However, iconographic evidence provides other clues. Justin Kerr's database includes an early Classic era vessel that represents the divine ballplayers; their yokes form the widest part of the object itself: