How the figures are calculated

Every lot comes from the auction house’s own published results: the lot page, the results list and, where needed, the sale catalogue. Each sale is checked against the total the house announced. The original title, description and identifiers of every lot are kept exactly as published; grouping and corrections are stored alongside, never over the source.

A lot is one car offered at one sale. A car is one vehicle across all its appearances: lots are linked when the manufacturer and chassis number match, across auction houses. A lot without a published chassis number stays unlinked rather than being matched on looks or description.

Sell-through is sold lots divided by lots offered. Offered means sold, sold after the auction, or not sold; withdrawn lots and lots with no recorded result are left out of both sides. A car sold after the auction counts as sold.

Prices are what the buyer paid, including the buyer’s premium, as published by the house. Hammer prices are worked out only where the house’s premium rate reproduces a round hammer figure. For comparison across sales, every price is also converted to euros at the European Central Bank reference rate for the first day of the sale.

Whether a car sold and whether its price was published are separate facts. A lot is shown as “Sold — price undisclosed” when the house confirms the sale but does not publish the amount, for example Broad Arrow and Gooding sales agreed after the auction. It is shown as “Price unavailable” when the result is a sale but the archive has not yet established why no price is recorded.

Both kinds count towards sell-through. Neither enters a median, range, total, ranking or resale figure, and an estimate or asking price is never used in place of a result. Every price figure is shown with how many published prices it rests on.

The median is the middle published price; the typical range is the middle 80% (10th to 90th percentile). Pages with only a handful of sales are marked as indicative. “Top models by sales value” ranks models by the total of their published prices in euros; only the rank is shown publicly.

A car counts as resold when it has two published prices at least six months apart. The change is first to latest sale in euros, so currency moves are part of it. It describes what happened to those cars at auction, not why, and a few resales are not a market index: the number of cars behind every figure is shown.

Lots are grouped by manufacturer and model from the titles they were sold under. Spelling and punctuation are ignored (Citroën and Citroen, 540 K and 540K are the same), but names that span different generations are kept apart, using model year and known production years: a 1957 300 SL (W198), a 1987 300 SL (R107) and a 1992 300 SL (R129) are three different cars. Where the year leaves the generation unclear, the lot is shown as unresolved instead of being guessed.

Groupings are being reviewed make by make. The breakdown of a model into its auction-title variants is only shown once it has been checked by hand.

Replicas, recreations and continuation cars; motorcycles, bicycles and scooters; and non-car lots such as automobilia, artwork, models, parts, radios, trailers and boats. Each exclusion follows a written rule that is checked against the lots it removes, so that cars with similar wording (a “Toy Tonneau” body, a “Twin Grille” roadster) stay in.

Spotted a wrong result, a missing price or a car in the wrong group? Email praveen@autokulturecollective.com with the lot link. Corrections are recorded with their source and applied at the next update.