Goals are posts which are set eight yards apart, centred at each end of the field. The surface of a polo field requires careful and constant grounds maintenance to keep the surface in good playing condition. During half-time of a match, spectators are invited to go onto the field to participate in a polo tradition called "divot stamping", which was developed not only to help replace the mounds of earth (divots) that are torn up by the horses' hooves, but also to afford spectators the opportunity to walk about and socialise.