Reply Peter van der Linden (North)
In his reply Ed made a point I was going to make. I mean the part where he writes that they don't know a lot in the South...
Indeed, people living near the fjords do know a lot more. To name something: they know how to google (this is a joke).
On googling, one of the things I found was that, although the principle of Puppet Stayman was invented by American Neil Silverman, it was his fellow Americans Kit Woolsey and Steve Robinson who extended Silverman's idea and published it in two articles in the 'Bridge World' in April 1977 and April 1978. A virtual forest of variations of this convention has sprung up since.
But your specific question is about the word puppet. I suppose it is used in the meaning 'marionette' or perhaps in a more metaphorical meaning as 'figurehead'.
The name has been given by Jeff Rubens, the editor of the Bridge World. I have not been able to find out what reason he had for his choice. Maybe it refers to responder controlling the notrump opener's bidding, as if the latter is a puppet in the hands of the puppeteer. But that is the case with many more conventions.
The following is not a reply to your question but I think it is useful anyway. In the original convention the 2♦/3♦-response of the 1NT/2NT-opener to the 2♣/3♣ enquiry, only denies a five card suit in a major (after that the 'puppeteer', if he is interested in finding a 4-4 major fit, bids the major four card suit he does not have; this continuation is common in all Puppet Stayman versions, as far as I can tell). So that 2♦/3♦ response of the 1NT/2NT-opener neither confirms nor denies possession of a four card major suit. Not a bad idea, I think, this way opener does not give away his hand.
In many other versions, for instance the one most popular in Netherlands (let's call it from now on the modern version), opener's 2♦/3♦ response shows a four card suit in a major (or two):
1 Puppet Stayman
2 Original version: denies five-card major; neither denies nor confirms four-card major
Modern version: denies five-card major; confirms four-card major (possibly two)
3 Four hearts
In the modern version South has shown four spades (3♦ showed at least one four-card major, 3NT denied four-card heart support).
In 'original Puppet' South has only denied a five-card major suit.
Admittedly: in the modern version South would, by responding 3NT over 3♣, deny both a four- and five-card major suit, meaning North has not given away his hand. In original Puppet, South having responded 3♦ (four-card major suit still possible), North will have to unveil his four-card major (by way of bidding the other major).
This looks to be six of one and half a dozen of the other, but still: if one of the players has to give away possession of a four-card major suit (with a chance of not finding a fit there), I prefer it to be the weak hand, who is certain to become dummy...
But to be completely honest: I do not know if the puppeteer can handle (and if so: how) this situation in the original version:
1 Original Puppet Stayman
2 Denies five-card major; neither denies nor confirms four-card major
...if he has both four-card majors, but cannot afford to go beyond 3NT.
Best regards from Orkanger
We have asked Jeff Rubens, editor of The Bridge World. His reply:
'In The Bridge World's terminology, a puppet is a transfer that systemically requires partner to make the cheapest bid. Puppet Stayman is so-called because in the original version a 2♣ response to 1NT required opener to bid 2♦ (as in Gladiator before it).
We emphasize that the opener was apparently under obligation to make the cheapest bid, whereas over a modern Jacoby transfer the 1NT opener can break the transfer if he has a good fit.