How the numbers are measured

Slope length: the one-way total across all runs, in kilometres. The best predictor of how many days a resort will occupy you.

Lift count: the number of named mechanical lines. Magic carpets in learning areas are NOT included.

Elevation range: the lowest and highest points of the ski area, in metres. For snow reliability the base is the number that counts.

Vertical drop: top minus base. A derived value; it is not a separate field in the source but computed here.

Usually not because one is wrong, but because they count different things. The three most common differences:

Magic carpets: some sources count learning-area carpets as lifts. The official Erciyes source says 19 installations while this catalogue says 14 — the five are carpets.

Round-trip counting: Turkish sources commonly publish roughly double the catalogue's slope lengths, possibly from counting runs in both directions.

Time: when a resort adds a lift or closes a section the number changes, but sites repeating the old figure do not update. Do not trust an undated number.

Because comparability is worth more than currency. Taking each resort's own most recent figure would make the columns meaningless: values measured under different definitions cannot be ranked.

The cost is clear: a resort's own site may differ from this one, and sometimes be more current. Resort pages point readers to the resort's own announcements.

The gain: the ranking in this table actually means something.

The risk of one source is that it is systematically wrong. To test that we compared two catalogue entries against independent official sources, and both matched exactly.

Two is a small sample but better than none, and we publish the result plainly: no sign of systematic bias. Cross-checked entries are marked ✓ on resort pages.

If you hold a primary source for a resort, write to us — we will verify it and widen the sample.

Keeping the catalogue internally consistent cannot be done by hand. A check script runs before every release and verifies: that the ordering is descending by slope length, that elevation ranges are valid, that coordinates fall inside Turkey, that derived functions agree, and that every region has at least one resort.

It also warns when a source verification is more than 180 days old, so information cannot go stale quietly.

For the five resorts with unknown lift counts the check warns but does not fail: the gap is deliberate and is never filled with an estimate.