The men's tennis GOAT question, settled the only honest way a librarian knows how — a transparent, weighted evidence synthesis. Move the weights, re-run the review, watch the field reorder — and discover just how stubborn the No. 1 really is.
Candidates were restricted to Open-era men who competed in the ATP Masters 1000 era (1990–present), so every criterion is comparable across every candidate — no player is asked to compete for a trophy that didn't exist in their career. Five names met the criteria. Zero were excluded. It is, as debates go, a small field.
Eight outcome measures were extracted per player (titles, weeks at No. 1, year-end No. 1, Masters 1000, Tour Finals, Olympic gold, total tour titles, and Slam-winning span). Each is min-normalised to the field leader and combined as a weighted mean. The Monte Carlo panel re-runs the synthesis across 10,000 random weight vectors to report how often each verdict survives — the tennis equivalent of asking whether a finding holds under any reasonable model.
Head-to-head, era strength, and the eye test are not modelled. Quality of competition, injury-shortened careers, and the pre-1990 giants (Laver, Borg, Connors) sit outside scope. Weeks at No. 1 and total titles reward longevity; Slam counts reward peaks — the weights are where you smuggle your priors back in, which is rather the point. This synthesis is not peer-reviewed, unless you count yourself, which today we do.