What is in nickname?

There are many cricketers having nicknames in cricket.Do you know Stuart Clarke have nickname Sarfraz?,Because of throwing ball like him.Many Australian cricketers have nicknames.Ricky ponting's nick name is 'Punter'.Adam Gilchrist's nickname is 'churchie',because after a cricket match a cricket fan approached Gilchrist and said, "Mr Eric Gilchurch can I have your autograph".Glen McGrath have nickname 'pigeon',which his colleagues have given because when he came first to play for New South Wales;he has very narrow legs like birds.Brat Lee have nickname 'Oswald',because during a match while reading name of playing XI by mistake Captain Steve Waugh read Oswald instead of Brat Lee.Brad Hogg had already left the job of Postman but he was famous as 'Postman' between colleagues(Now he have taken retirement).Brad Hodge is called 'Dodgewall' because of throwing dodging balls.Michael Clarke is famous as 'Pup' because of young impressions on his face,He says,"At least now change my name".New Zealand cricketer Peter Fulton is called 'Two meter peter' because of his tallness.