Posted 2013-September-19, 12:44
none
of course it will sometimes work but not often enough for me.
it has three ways to lose
we go 800 ... ouch
we could beat them in 4 especially if I keep my mouth shut (I mean RHO may have only a game invite on the 1st hand according to the OP, and dummy may have a misfitting hand with spade values, so while game will usually make their way, it isn't a slam dunk)
we could be defending 5♥ with partner now making a terrible lead from say Kx or Kxx in spades, with a safer and more common lead had we not bid.
So 3 ways to lose, one way to win, and no clear reason to think that the latter outweighs the former.
'one of the great markers of the advance of human kindness is the howls you will hear from the Men of God' Johann Hari