An opening bid of 2NT can often contain a five card major and basic Stayman can not locate a 5-3 major-suit..
Puppet Stayman, invented by Kit Woolsey and Steve Robinson, is a variation of the Stayman convention intended to solve that problem. It serves two purposes.
▪ It allows the side to find a 5-3 fit when the notrump opener has a 5-card major.
▪ It allows the side to find a 4-4 fit without revealing unnecessary information about the notrump opener's hand to the opponents.
Puppet Stayman is most commonly used after a 2NT opening. Some have explored it's use after 1NT but this has not established itself as a popular notion.