Dinarius, on 2015-July-06, 13:58, said:
Ps. If double isn't available, I bid 4 diamonds - obviously asking for a major.
That meaning may be obvious to you but I very much doubt that it is obvious, or even plausible, to many others.
The cuebid of the opps' suit has evolved over the years. It was commonly played, back in the dim, distant past, as promising 1st round control of the suit, a big gameforce hand, and said nothing else...so no inference about support or holding a suit or suits of one's own.
That usage died out as players realized that requiring 1st round control limited its frequency
So it became a GF action, still unlinked to any other information about the hand.
Then that became outdated because players realized that finding fits early was important, especially as bidding became generally more competitive, with far more pre-empts than existed back in the 1950s or 1960s.
The cuebid then became a gf raise, but this, too, became outmoded, again probably at least in part to the tendencies to more aggressive action by all seats.
So responder's cuebid, as an initial action, of an overcalled suit, is generally played as a raise of opener's suit, invitational or better, tho obviously when the cuebid is, as here, 4
♦, it is forcing to game. Indeed, it would be normal to play a 4-level cue as showing a stronger raise than a direct game bid, classically in the majors....say 1
♠ 3
♦ 4
♦ is a full-values 4
♠ raise, with some extras, while 4
♠ would be at most a minimum opening bid.
Clearly, one could agree that in the OP auction 4
♦ is the majors, but one has to ask 'why?'
With real majors (5+ in at least one of them), why not bid one? With 4=4 why not double? And how else is one to bid a really good hand in support of clubs?
'one of the great markers of the advance of human kindness is the howls you will hear from the Men of God' Johann Hari