Complex sentence: There is a special space above the game board reserved for offerings to Macuilxochitl, into which a player must place one of his treasures each time his toss results in a score of zero (no holes showing).
Split into simpler sentences: There is a special space above the game board reserved for offerings to Macuilxochitl. A player must place one of his treasures into this space each time his toss results in a score of zero (no holes showing).