its to the ball bag....... example, in the summer rover stands 19"s to the ball bag, yet in the winter rover stands 21"s to the ball bag... its an imperial measurement .... p,s fluctuations must be made accordingly to the weather... ie all ball bags will be longer and danglier in the warmer months resuling in a lower hight to the said ball bag in question,,,,,,,,,, i hope this clears up the subject once and for all atb the yoggerman