Lead conventions have their place in the game as one of the critical ways defenders can legally “talk” to each other to describe what they hold in a particular suit when they choose that suit for an opening lead.
This language will never be totally decipherable by the receiver of the lead, but there are certain vocabulary components that can definitely help.
Such as the lead of a low card when the leader is known to have some length in the suit denotes possession of an honour card where the lead of a relatively high spot card denies possession of a possibly useful honour card. There’s even a useful acronym as a memory aid: BOSTON as in “Bottom of Something, Top of Nothing.”
When this deal was contested during an online practice session, West spoke in one language while East “heard” his partner in the more traditional fashion as detailed above and the breakdown in communication was calamitous.
North scraped up a raise of his partner’s weakish rebid to land in a contract that appeared fated for down one with the loss of one trick in each of the plain suits and two trump tricks thanks to the nasty split.
Down at least until the early play as West led the spade deuce to the Jack and ace. Declarer played back a diamond to a heart discard (gulp!), dummy’s Queen and East’s ace.
And back came the Queen of spades to end South’s worries!
Having located all the top spades except the King at trick one, East “knew” his partner would have that King for the initial low lead! And, well, he should have!