Against a bidding sequence of 1NT, 3NT, partner, West, opens with what looks like the fourth highest of a suit. Dummy goes down with two small cards in the suit. I have four to the king in the suit, two of them little ones, with this question revolving around my second highest card.
I take the king, which is allowed to hold. If my original holding was something like K642, I was taught to return the 2, my original fourth highest. On the other hand, if my holding were KJ42, with the second card being the J, one is supposed to return the Jack.
With KJ2, I would return the Jack to "unblock." Does a similar reasoning hold here with two small cards?
One thought is that partner (West) and declarer (South) probably have the ace and queen between them. If South has Axx, it doesn't matter what I lead, but if South has Qxx, leading the Jack will "trap" the queen. Is that the reason to lead the Jack?
More to the point, how high does my second card have to be, before I lead it in preference to the 2? That is, would I also do this with KTxx or K9xx?