Posted 2013-October-12, 04:06
There are a few guiding principles to when Blackwood is the most appropriate tool.
One (as already mentioned) is that you should try to avoid it when you have a side suit that is potentially wide open to two cashing tricks. If partner comes up with fewer than all of the missing Aces, you are left in doubt whether he has the Ace of that suit and, if not, whether the King is also missing in that suit. You lack the ability to enquire about the King without committing to 6 in its absence, whereas if he has that King then the missing Ace is likely the only trick for the defence.
Another is that you should try to avoid it when you have a void. If partner comes up with at least one but not all of the missing Aces then you are left in doubt whether he has the Ace opposite your void, when it would be more useful in another suit where you are also missing the Ace.
Sometimes you have no better alternative way of investigating slam, either because you have no other tool at your disposal or because those other routes have their own (greater) potential flaws.
On this hand the 4H response contributes to your problems, but that aside, were you as opener (say) to cue bid 4S to show a Spade control and interest in Heart slam, then this would give partner the opportunity to cue the Club Ace if he has it, or perhaps for him to use Blackwood on opener, already aware of the Spade void (he having the AK opposite the suit cue bid).
But cue bidding (over a 4H response) is not guaranteed to get you home. Responder may have (say) KQ of Clubs and choose not to cue bid 5C, and you are left in doubt whether 6 is safe.
"5 or 7" hands are rare beasts. These are hands that make 11 or 13 (but not 12) tricks. When they arise, the break-even probability of making 7 that justifes bidding it is very low, well below 50%, contrasted with other slam bidding. But it is very hard to recognise and evaluate these hands at the best of times, and particularly so when that probability of success relies on a finite chance of a non-optimal opening lead, which probability in turn varies according to how revealing is your route to slam.
Ironically, use of Blackwood on this hand is probably the route which gives you the best chance of bidding and making 6 (with the overtrick in this case). Cue bidding controls scientifically on the way to slam also tends to pinpoint weak suits vulnerable to attack on opening lead. Likewise just blasting to 6H directly over 4H tends to telegraph the possibility that the opening lead is critical, which tends to favour leading an Ace (or away from a King). If they trust you to have a hand suitable for Blackwood, then as with any psychological strategy, that trust may be their undoing.
At the level of experience suggested by the OP I would suggest keeping it simple: forget about the "5 or 7" factor, try to stick to the golden rules for when to use Blackwood, and be content with making 5 +/- overtricks on this hand.
Psych (pron. saik): A gross and deliberate misstatement of honour strength and/or suit length. Expressly permitted under Law 73E but forbidden contrary to that law by Acol club tourneys.
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Masterminding (pron. m
s
t
r-m
nd
ing) tr. v. - Any bid made by bridge player with which partner disagrees.
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