That is actually a Horrible head movement drill you want the object you are avoiding to be the size of the Glove the opponent is going to be wearing if you use something bigger than the Gloves boxing uses you are teaching your mind and eyes to slip and roll a distance that is more than what is actually needed thus you make your self use more energy than is needed so you ruin your energy management abilities in a Fight if you slip and roll a bag like that measure a sand bag and make bags that are 8 oz 10 oz 12 oz 14 oz and 16 oz slip and roll only bags those sizes for those are the size of Gloves
That is actually a Horrible head movement drill you want the object you are avoiding to be the size of the Glove the opponent is going to be wearing if you use something bigger than the Gloves boxing uses you are teaching your mind and eyes to slip and roll a distance that is more than what is actually needed thus you make your self use more energy than is needed so you ruin your energy management abilities in a Fight if you slip and roll a bag like that measure a sand bag and make bags that are 8 oz 10 oz 12 oz 14 oz and 16 oz slip and roll only bags those sizes for those are the size of Gloves