Posted 2019-July-31, 10:57
As Nige1 and pescetom suggest: pass
Now, this is an unusual situation (of course all 1S 4H sequences are rare) in that presumably South could have bid 4N as keycard, assuming keycard is in use. I am in fact struggling to construct a hand where 4N makes no sense and 5H does.
If one is using ordinary blackwood, then the issue disappears, since ordinary blackwood doesn't help (at least immediately) with the heart King and not at all with the heart Q. Now 5H is the only reasonable action for a south with a good hand, and side Aces, and poor trump: how good are your hearts, partner?
In any event, 5H is not forcing, simply on general principles, and this hand is clearly not a 'good' 4H bid. I am not criticizing the call: I am merely pointing out that North will often/usually hold a better suit for the action: KQJ10xxxx being a reasonable example.
If South had keycard available, then the 5H is odd unless he was unsure that you'd understand that 4N as keycard. With an expert partner, I'd infer a void (presumably in diamonds) such that the keycard response of, say, 2 keycards would leave him guessing. Say AKQxxx xx void AKxxx.
In any event, no matter what partner thinks he is asking, I don't have it. So pass
'one of the great markers of the advance of human kindness is the howls you will hear from the Men of God' Johann Hari
deep asks 'what bid now south?'
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The normal message of 5♥ is good plain-suit controls but worry about trump (♥) quality e.g.
♠ A x ♥ x ♦ A x ♣ A K Q x x x
so PesceTom's recommendation of Pass seems good advice.