[davidk1964]

In the show solution discussion it says "the good news for South is that the spot cards played by the defenders strongly suggest that spades are 4-4". I understand what follows from there if you believe the spades are 4-4 but I'm not sure how the spot cards strongly suggest it? Is it that the lead is assumed to be 4th best and you have the 2 and 3? Also does this hold in more "modern" times with less adherence to strict following of leading guidelines? E.g. what if a canny defender led the 7 instead, or from 3 cards headed by the Ace?

[smerriman]

There are certainly *alternative* leading conventions to 4th best, but in "modern times" defenders still stick to their system, rather than just leading randomly. I don't know anyone who would agree to lead 7 from A764; if West chose to do it just to be 'canny', it would certainly backfire as I would believe them as East and switch to another suit.

Low from Axx by itself is definitely a valid lead, but East would then have returned their original 4th best, which can't be the lowest remaining card; pretending to have 4 would again backfire and mislead partner more than declarer.

With both playing their lowest cards, 4-4 seems likely regardless of what leading system they're playing (though 4th best is probably safe to assume in BridgeMaster in general).

[thepossum]

I imahne it helps if a partner understands what a lead could mean
A strange thing I have discovered running my meaningless sims is how often a low lead from long works even if partner doesn't know

[davidk1964]

Thanks for the replies! I hadn't got back to this sooner as assumed I'd get an email notification.