[kenrexford]

Any thoughts on the following?

A common problem that I seem to face is mis-reading the opponents. This problem is often noted to me by partners. I'm not sure whether partners only see the minority of reads that fail and that the majority actually succeed, or whether there is a strain of problem situations where I consistently expect too much from the opponents. I posed one specific problem to a good player and heard the response to do one thing "in this field" but another thing in a different field, whoich made me think.

The specific problem could have a hand diagram, but it is rather simple, and I'd rather not have any possibility of a mathematical solution interfere with the psychological. I'm also changing something to remove a Smith Echo solution.

Your partner, against 3NT, leads the 10 of a suit. Systemically, she could have 10-top, K109, or Q109. The lead appears to be from length. (As an aside, does "Power Tens" solve this problem, the Q109/K109 problem?) Dummy ducks with Axx and Declarer wins the Jack. (Note the side issue that falsecarding Queen from QJx would be stupid here.)

Anyway, if you get in early, which is unexpected, you could lead partner's suit back. If partner has a late entry, then K109x(x) would be established. Q109x(x) would not.

Dummy also has a small stiff in a major bid once by Declarer; the entire auction suggests a 4441 layout in this suit. You hold KJxx. If partner has A108x or Q10xx, a switch to the Jack after an early entry looks nice.

So, Declarer surprises you by allowing you to gain entry fast. At trick two, your Jxx in diamonds (dummy has five; delcarer seems to be missing the Ace and Jack only) provides an immediate entry when Declarer leads the 9 past K108xx into you. Weird.

It seems that Declarer would avoid allowing entry to your hand as the first loser. You would not have hooked this way, unless perhaps you were prepared for the return of the opening-lead suit but not for a switch. Bidding would provide Declarer no good info.

So, do you assume that Declarer made a weird play, or do you assume a smart play and switch to the stiff major?

Now, if I have the analysis off, as to what Declarer might be thinking, then great. Note that and then address the greater and intended issue of how you generally decide whether Declarer is wise or not (if willing to share that nugget). The answer I received in SF was to return partner's suit in this event but to switch to the major in a better field.

[skjaeran]

My experience is that when you have to make a choice of this kind it pays off to assume declarer made a mistake, unless you're playing against a very strong player. I've often been assuming that opponents doesn't make these mistakes and haven't been able to capitalize.

[dake50]

A friend of mine has a quote "I might be outsmarted on a hand, BUT I will never be out-dumbed". Assume declarer made an error.

Post-mortem note the clever play, but never expect it.