The general approach seems to be to try to make the holder of the doubleton trump to win the first club lead.

East promised only five spades. Is that hand so much more likely to have a singleton trump that is worth giving up the heart finesse?

The opening lead also placed the top spades in the East hand. Especially as a third hand opener, East did not need more than one of the three non-spade high cards, so any extra chances stemming from East having both club honors due to the bidding seem really small to me.

My rude calculations seem to favor the “mundane” line.

Hi Jim2,

Your interest in specific card and distribution pinpoints helps stimulate my answer.

While a general probabilities feel should enable the declarer to determine percentage likelihood, the tempo at the table is usually more to the point. The evidence of whether you, as South the declarer, thought West, at the table, was considering bidding something, (no doubt, in this case, 5 spades) over your preempt or rather was just biding his time and was always going to pass, as well as the opening bidder, upon the bidding reverting back to him, actually considering or not soldiering on, is, at least to me, the straw that may help you determine what to do in the play.

The lesson that now should come forth to the would be expert is, at least, some of the above, but, just as importantly, when on defense, herky-jerky inconsistent tempo (while not being an unethical tell to partner) now serves as also not being a tell to a very shrewd declarer.

It then follows that a defender should never, by his tempo, help his partner determine his strength by anything other than his bid itself, but at the same time, his table behavior does not owe the opponents any extra benefit either.

For what it is worth, usually a player having two small instead of a singleton in the opponents suit, is MUCH less likely to be considering bidding on.

Your query regarding card reading 101, concerns itself with separating the sheep from the goats, among the very top players.