One strong, relevant link generally beats ten weak ones, but the honest answer to “by how much” is that no single number captures it. The direction is clear because authority and relevance concentrate value: a link from an established, topically related source passes far more meaningful signal than a scattering of links from low-quality or unrelated pages. The magnitude is not clear, and any precise multiplier you have seen is invented, not measured.
The direction holds because of what each kind of link actually carries. A strong link comes from a page that itself has standing and sits in the same topical neighborhood, so it transfers genuine authority and a relevance signal that says the right kind of site vouches for you. Weak links come from pages with little authority, little relevance, or both, and value that is small per link does not become large by repetition. Ten near-zero contributions sum to near zero, while one substantial contribution stands on its own.
Now the refusal, which is the more useful half. People want “one strong equals ten weak” as if it were a conversion rate, but link value is not denominated in a public unit, the engine does not expose it, the weights are not fixed, and the strength of any single link is itself a spectrum. So a clean ratio dressed up as measured is fiction. The truthful statement is qualitative: the strong link is worth materially more, often dramatically more, and the exact factor cannot be pinned because the underlying quantity is not something anyone can read.
Refusing the fake number is not hedging, it is the accurate answer to the part of the question that has no accurate number. Saying “direction yes, multiplier no” leaves you with the part you can act on and protects you from planning around a figure that was never real.
For your next link effort, spend it pursuing the single relevant, authoritative link rather than assembling a pile of weak ones, and ignore any source that hands you a precise strong-to-weak ratio, since that number is manufactured.