About item statistics on backpack.tf
Stats are gathered by parsing inventories as they are loaded on-site. We log every new item we see to
Elasticsearch, and this information is used to populate data for item
histories, the Premium search system, and of course detailed statistics for each item.
There are, however, some caveats to doing this:
We are unable to process private inventories. Items inside these inventories will not be considered to
exist until the inventory is made public or the item moves to a public inventory.
As of October 2014,
inventory privacy has been set to Friends Only by default. Because of this, older TF2 statistics are
relatively more complete, and many unpopular items found in the inventories of non-traders will be
We will always lag behind by a few minutes. Displaying up-to-date statistics on items is an expensive
process, so extensive use of caching is done to make sure we don't hit the item index too hard.
Some statistics such as owner count are a little fuzzy for performance reasons.
In other words, don't expect perfect statistics, for that is virtually impossible for anyone
outside of Valve to attain.