gnasher, on 2014-August-17, 05:14, said:
Aren't I North?
You are, but it is South who led against East's Four Spades. It is South who may have have six or seven diamonds, and North who made the takeout double of spades and who has the defensive problem at trick one, which it seems that only jallerton solved.
If you mean that North will think South would have bid Four Diamonds with Jxxxxxx, then he might well. Even more reason for him to play South for six, unless the lead has to be systemically from seven.