Retired spin king Saqlain Mushtaq on Monday defended the controversial "doosra" delivery he invented, which has come under renewed scrutiny since fellow Pakistani Saaed Ajmal`s chucking ban last week.The doosra, which means "the second one" in Urdu, turns from legside to offside -- the opposite direction to orthodox off breaks.It is bowled from the back of the hand with a lot of top-spin, though the bowler`s wrist still moves in a clockwise direction, making it difficult for a batsman to pick.Saqlain is credited with its invention, adding to a list of Pakistani innovations in cricket including the batsman`s reverse-sweep and reverse swing bowling.But the delivery has come to be regarded with deep suspicion by many, particularly in Australia and England, where critics charge that doosra bowlers bend their arm beyond the permissible 15 degree limit.