Answer-first
Also known as: inverted pyramid, answer up front, lede
Putting a direct, self-contained answer in the first paragraph after the H1, before any explanation or context.
Retrieval systems quote the first passage that stands on its own. An introduction that warms up for three paragraphs before reaching the point gives them nothing to lift, so the page loses to a worse article that answered immediately.
The measurable version used here: within 1500 characters after the closing H1 tag, there is a paragraph of at least 25 words. That is the same window and the same bar used by the two sibling checkers in this portfolio, deliberately, so the three tools never disagree about the same page.
Answer-first is not the same as short. The answer goes first and the article can then be as long as it needs to be. What gets cut is the throat-clearing, not the depth.
It is also the one signal on this list that improves the page for humans at exactly the same rate it improves it for machines, which is unusual enough to be worth saying.