jallerton, on Apr 22 2010, 05:47 PM, said:
As Robin explained earlier, West was under the impression that East had forced to game. With ♠Jxx, would West have much interest in defending 3♠x at unfavourable vulnerability? If not, presumably West would bid 4♥ over 3♠ from South.
If west thought they were in a game force it should be considered that west might make what to him is a forcing pass, either in case east could bid 3NT, or in case east could double, or because bidding shows a better or more offensive hand to them. Or since west thought 2NT was jacoby they might have the agreement that bidding right away say something about a spade control. There are so many reasons west might pass.
It's far too simplistic to say "they are forced to game so west will just bid game". At the very least it should be looked into whether they have any agreements after interference over jacoby 2NT. If they don't maybe it's time to poll some peers of west with the auction as west perceived it.
Please let me know about any questions or interest or bug reports about GIB.
1♥-X-2NT*-4♠
AP