Opening the book…
A number alone invites you to supply your own explanation, and you will supply a flattering one when the number is good. Forcing the owner to write the causal story surfaces whether they know why it moved, and the absence of a credible story is itself a strong signal. Reading the account first stops the number from anchoring your judgement of the explanation.
Ask for a few sentences with each reporting cycle: what moved, what caused it, what you expect next period. Reject accounts that only restate the direction of travel. In the review meeting, have the narrative read before the figure is shown, and ask follow-up questions about the mechanism rather than the magnitude.
Stable measures sitting inside their normal range need no narrative beyond confirming they are stable. High-frequency operational dashboards checked many times a day cannot carry a written account each time; apply this at the reporting cadence, not the refresh cadence.