Do you know what are the benefits of using a speedball ? Is it actually a speedball? I 'd like your opinion and please post any drills(if there are) you might know.
hand eye coordination, timing and speed. drills: one-bounce, two bounce, one bounce left right, two bounce left right, round about...
Speed Bag Benefits I found this list of Speed Bag Benefits posted on Speed Bag Central.com http://www.speedbagcentral.com/SpeedBagBasics_Introduction.html#A
I'll chime in here with timing, shoulder strength, everything else mentioned and add......My copy of Dempsey's Championship fighting is out on loan at the moment so this is going by memory......Dempsey say the speed bag lets you practice the downward chopping parry followed by a backhanded strike. Not very useful with gloves on but Dempsey fought most of his fights bareknuckle in the lumber camps and so on during his youth.
It also teaches you to "pop" you're shoulders to get an extra spark of power in your punches. That's some good stuff right there, that "pop"