Google evaluates three sub-components independently. Expected CTR predicts whether your ad will get clicked, based on historical performance for that keyword and match type. Ad relevance measures how closely your ad copy matches the searcher's intent. Landing page experience assesses load speed, mobile-friendliness, content relevance, and ease of navigation. Each sub-component is rated "Below Average," "Average," or "Above Average," and these combine into the 1-to-10 score. The practical lever is this: fix whichever sub-component is dragging, and the score moves.