Just Checking...
Law 16B1 states that partner's failure to alert is UI.
Fair enough.
What about failure to alert a bid that should not be alerted?
S N
1D 1H
3C (not alerted)
3C was intended to be a splinter but S mistakenly jumped one instead of two levels. A misbid rather than an unintended call.
Is it UI?
I think so, but it's certainly slightly greyer than a normal failure to alert.
It feels a bit like when partner makes a jump bid without playing a stop card. Were they just being lazy or did they not realise it was a jump bid?
The consequnces of it being UI is, of course, that S is not allowed to know that she has not shown heart support.
Comments
Yes, I think this is UI. What is more important than whether a bid should have been alerted is whether the player was expecting an alert, as is the case here - I've just checked, the language in 16B talks about unexpected alerts, not mistaken ones. Ideally, a player shouldn't be gaining information from their partner's alerts (or failure to alert).
Bids above 3NT (after the first round) are not alerted, so South should not expect an alert in this case. But let's say her partner is trigger-happy with the bidding box, playing at the turn of the millenium and usually alerts these Splinters. At some point South could realise that she has misbid - does the UI mean that she isn't "allowed" to realise her mistake?