Role of the Staple on a hammer

[Cliff Lesher]

Some manufacturers use hammers with staples all the way to 88, e.g.  
Yamaha.  Others use hammers with staples only to the 60s, e.g.  
Petrof.  I've never heard a good reason for the difference.  I've  
heard guesses.  Anybody know for sure?

Cliff Lesher
Winfield, PA