Conventional leftism (CL) is when you receive a multi-card clue and play the newest of them while it is not logical to do so.

For example you have Y4 Y3 in hand in this order (say second and third slots).

Y2 has just been played.

You receive a yellow clue. It's not logical to assume the leftmost one is playable, it's only conventional.

Sticking to logical leftism (LL) means you will play the newest card of a multi-card clue only if it looks like this card has been awaited for some time and you've just drawn it and your teammates give you the clue for this reason. And other logical situations.

LL may sound less efficient than CL, but it really works. Most importantly, it makes it possible to handle some situations conventional leftism can't solve (wrong timing and a multi-card clue would result in a wrong card being played) and to give pure clues that might become spoiled if you let the player draw another card.