The methodology behind Maison Montres' authentication protocol, condition grading, market data, and the Maison Montres Collector Index. We document our methods so collectors and competitors can scrutinise them.
Methodology pages exist for two reasons. The first is internal discipline: a published methodology is one that must be followed. The second is external accountability: collectors, journalists, and other advisory houses can scrutinise our work and challenge it where it is wrong. Both are useful pressures.
Every watch authenticated by Maison Montres passes the same twelve-point protocol, documented in detail on the Authentication Service page. Each point is signed off by a named watchmaker; vintage references and complications above CHF 50,000 receive an additional two-tier review by an external specialist with no commercial interest in the transaction. The full report is delivered to the collector with photographic evidence at each step.
What we do not do is also part of the methodology. We do not "guarantee" provenance we cannot independently verify; where a watch arrives without primary documents and the historical record is silent, we report that gap rather than imply it does not exist. We do not certify watches we have not physically examined. We do not authenticate from photographs alone. This conservatism is the source of the lifetime guarantee — we only stand behind what we can defend.
Maison Montres grades condition on a 1-to-10 scale across four axes — case, dial, movement, bracelet — with photographic evidence supporting each subscore. The composite grade is an average, not a marketing aggregate. A watch with a perfect dial (10) but a polished case (7) and stretched bracelet (6) does not become an "8 out of 10 collector example" by averaging; we publish the four numbers separately so the collector reads the composition, not the average. Definitions:
Subjectivity is unavoidable in condition grading. Our internal training requires every grader to align with at least two senior watchmakers within ±0.5 on every reference; outliers trigger re-grading.
Editorial pages on this website — particularly the Watch Investment Guide and reference-specific pages such as Patek Philippe Nautilus — cite compound annual growth rates (CAGRs) and price ranges. These derive from the Maison Montres tracked-reference dataset, which combines:
Sample sizes vary by reference. Common references such as the Patek Nautilus 5711 or AP Royal Oak 15500 carry hundreds of data points per year; vintage references such as the 1518 or 2499 carry tens. Where sample size is too small for reliable inference, we say so explicitly and report a price range rather than a CAGR. The complete tracked-reference list and source citations per reference are available to retained Tier II and Tier III clients.
Limitations. Past performance is not predictive. Concentration of supply (e.g., Patek discontinuation events) creates non-linear price movements that historical CAGR cannot extrapolate. Liquidity in luxury-watch markets is structurally lower than equity markets — bid-ask spreads of 5% to 15% are normal. The data is best read as informed market commentary, not as a financial-instrument price feed.
The Collector Index ranks fifty named celebrity collectors on the documented quality of their watch collections. The methodology is structured to favour rigour over breadth.
A piece counts toward a collector's verified-pieces total only if it has at least one primary citation: a Hodinkee Talking Watches appearance, a Hodinkee Magazine attribution, an auction provenance record (Christie's, Sotheby's, Phillips), a brand ambassador disclosure, or a named-source confirmation that we have triangulated against at least one secondary source. References that appear only in social media posts or third-party compilations without primary citation are listed as "Reported, unverified" but do not count toward the verified total.
Estimated value combines the verified-pieces count with current-market secondary pricing for each reference. The range reflects condition uncertainty (worst-case to best-case condition for unverified examples) and incorporates the lower end of dealer-bid prices, not retail. Estimated values are conservative by construction.
The Collector Index is a public-record exercise. Genuine private collectors with no public footprint do not appear, even when they are known to specialists. We err on the side of citation rigour, which means we exclude references and entire collectors where the public record cannot bear weight. The next annual update is scheduled for May 2027.
This methodology page is reviewed annually each May. Material changes — new authentication checkpoints, expanded grading criteria, additions to the tracked-reference dataset, Collector Index methodology updates — are version-stamped in the document history below. Minor clarifications are not version-stamped but reflected in the "Last Updated" date at the top of this page.