Source: www.acblunit390.org

When partner opens 1NT and you know they could possibly have a 5 card major you can jump to 3as Puppet Stayman so long as you have these requirements:

• Game Forcing Values
• One or both Majors. Either 3-3 or 4-3. Never 4-4. With 4-4 use whatever version of Stayman you play.

Responses by opener to 3are:

Version 1

• With a 5 card major bid it.
• With no 5 card major or 4 card major bid 3NT.
• With one or both 4 card majors bid 3. Responder if interested in finding a 4-4 major fit can now bid:
  • 3 of the major they do not have which shows 4 of the other major.
  • 4which asks opener to pick their major. (Because responder is 4-4)

Version 2

• With a 5 card major bid it.
• With no 5 card major bid 3. Responder if interested in finding a 4-4 major fit can now bid:
  • 3 of the major they do not have which shows 4 of the other major.

I like version 2 better because less is revealed about opener’s hand.

Justin Lall wrote a good article about the reasons for using version 2.