insufficient bid after rkcb 5nt

[David Graham]

Just a quiry I would like the panels opinion .
After an agreed suit between east/west , east called 4nt rkcb , west called 4 diamonds (insufficient & unintended) the director was not called the offer to accept the call was not given the call was changed to 5 diamonds & the auction continued on to slam.
I was asked later what I thought by the north south pair my immediate thought was that west could change his call to what ever legal call he wished but east would be barred from the auction but law 27 1 (b) might negate that , does an unintended 4diamond mean the same as 5diamonds response to blackwood the information has been given to east anyway.

[Ed Reppert]

If it was unintended he can change it to his intended call without penalty. Law 25A.

[Chris]

An example given in the explanation of the new Law 27 (Insufficient Bid)  by Ari Geursen on behalf of Zone 7 shows -

W      E
1S   - 3S
4NT - 4D

and the accompanying text says - "If the Director is satisfied that East was answering Blackwood but at the wrong level, then East will be allowed to correct to 5D without penalty.

[Matthew McManus]

There is a difference only in what Law is used to allow West to change 4D to 5D without penalty.

If the director rules that it is unintended, then it may be changed under Law 25A. If an insufficient bid, then it can be changed under Law 27.

The only material difference, although probably irrelevant, is that if North made a call over 4D before the director was called, then under Law 25, the auction could be returned to West for 4D to be changed, but if the ruling was made under Law 27, then the auction would continue without penalty.

[Ed Reppert]

Well, there's a difference in that an unintended bid (Law 25A) conveys no UI. In particular, this means there is no basis for a later score adjustment when 25A is applied, while there may be in some Law 27 cases.

[bluejak]

Another difference is that the next player may accept the insufficient bid under Law 27.

Another difference is that the player has other options under Law 27 - perhaps he might decide to bid 6NT.  That may sound unlikely, but it is the player's choice, not the Director's.