quiddity, on 2012-November-16, 12:59, said:
By this logic, partner would also not bid 3D with a natural 3D bid since it is very likely to be misinterpreted. I would probably never bid 3D with any hand undiscussed, but I doubt many people would think that we would take it as natural.
Your thinking is a good reason for the metarule "if it can be natural it is" but it is too hard on a new partnership to assume this thought process is univeral.
It is more likely that partner never considered that we would take 3D as natural since it is a very atypical way to play, this is even more true if he knows we have some diamond length (if he has heart length which he probably does). Maybe he just wanted to leave us room to bid 3H who knows.
I would suggest that just based on common sense your conclusion to take 3D as natural comes from a thought process that is too convoluted. Here you are playing partner to have a natural 3D bid which is almost impossible given our hand, and for him to have made a natural 3D bid even though that is a non standard way of playing that is very accident prone in a new partnership. I understand your reasoning for why this should be the case undiscussed but most people at the end of the day will not bid a natural 3D and expect you to be on the same page, they will be scared of an accident. There are many ways to think about a problem or a situation, and situations where you have no rules and agreements are interesting, but that is the problem, there are many ways to think about it and your partner might not think about it the same way, even if they are VERY GOOD. There is no reason to punish partner when we know almost for sure that it was a spade raise, even if he could have/should have bid 3H instead.