awm, on 2012-March-30, 14:08, said:
I didn't want to post earlier b/c this is the novice/beginner forum and I think this point is perhaps too advanced. But here goes....
Its MP, and you are in an unusual contract. Most will not open 1nt on this shape, and will reach a spade contract. You cannot do anything about people in 6S so you should consider how your result will compare to 4S.
If spades are an fact JTxx on your left, the people in 4S will lose a trump trick and a heart (no one leads a spade against 4S from JTxx). So making five in NT will be excellent. Cashing spades from the top is fine. However a 3-2 spade break people in spades make six. To beat them you also must make six, so cash from the top.
This has little to do with "how people lead" -- it's about MP strategy.
True EXCEPT if diamonds are 3-3 and there is no heart opening lead then people in spades will often make 7 by ruffing a club and running diamonds (throwing a club on the third diamond and planning on giving up a heart if diamonds don't break). I still agree with your point because that situation is too big of a parlay, but it's worth considering.
I also agree with the point that most people wouldn't lead J from JTxx against 1NT - 3NT. Still, some would (even though they really shouldn't), so you have to consider it. More people would have JTx but of course then you don't have to finesse anyway.