rhm, on 2018-October-26, 11:59, said:
Works also on 4-2-3-4
Rainer Herrmann
Or 4-1-4-4 with or without the king of hearts. That might be enough to swing the play in favour of rising at trick 1, and drawing two rounds of trumps, especially as I think the heart lead from Kxxxx(x) is unlikely. It might let through a no-play slam when dummy has
♥Ax(x) of hearts opposite
♥Qx(x).
I investigated this some more. Finessing the heart, assuming that the opponents will always lead a heart with or without the king, works about 80.4% of the time, whenever the heart finesse is right and clubs are not 5-0, and also when clubs are 3-2 and there is no heart ruff.
I think that rising with the ace of hearts is clearly right. That works in the following cases:
a) Clubs 3-2: 67.8%
b) Clubs 4-1 and QJx or QJ tight in diamonds in either hand: 2.9%
c) Clubs 4-1 and diamonds (otherwise) 4-3 with 4-club hand having 3 or more spades 9.78%
This totals pretty much the same, 80.48%, and is slightly better even against Gabriel and Jophiel who will unerringly lead a heart with or without the king to give you a losing option. Actually, against those two miscreants it does not matter what you do - if you rise with the ace it will be ruffed and, if you finesse, East will win and give his partner a heart ruff.
I prefer to give the lawmakers credit for stating things for a reason - barmar
IMPs Lead 9♥
From the Welsh trials. BBO readers get two for the price of one here, with the first problem to play 6C, after North's intelligent choice on his final call, on the lead of the 9♥ and the second is to play 6NT by North, on a similar auction, on the lead of the ♣J from East.