Thank you for the answer Mike. (I didn't understand the 2 previous posts and wondered what was wrong with OP. Your answer was a relief.)
mikeh, on 2012-November-17, 14:39, said:
....
So we play A and a diamond and (not surprisingly) East wins and leads a small club.
This is simple. Your play here doesn't matter unless you play high! Put in the 9. If covered by the 10, win and play to the J. Or, equally valid: put in the J, and if covered by the Q, win and play to the 9. There is zero difference between the 9 and the J in terms of which one to play 1st.
Yes, that was a stupid question. (When posting I thought that I had to do this correct from the first time

)
mikeh, on 2012-November-17, 14:39, said:
It is tougher at mp and toughest at BAM. If the diamond hook were to win, we'd virtually claim the overtrick since it is very unlikely that the multi opener held x AKxxxx Kxx Qxx or the like. But I doubt that West would switch to the diamond 8 at trick 2 with that hand. It would be a good psychological move against me, but few players see that deeply into a hand that early. I think he'd switch to a trump.
It was MP's, but against Jack. I was almost sure that RHO had
♦K.