For me

Distinct builds deployed to a game's public (default) Steam branch, as Steam's client network describes them.

Checked within minutes of each Steam change. Observed since 21 Oct 2026.

• We see a game's builds only from the day we started watching it. Before that we know just the build it was on, so counts over a window are shown only for games watched for the whole window.
• A build is not necessarily a content update: developers also ship fixes, and some builds change only files players never see.

Source: Steam client network (PICS), App info, public branch. Full methodology

Posts in a game's official Steam news feed that announce an update: tagged as patch notes by the developer, or plainly about a patch or a released update.

• An announcement is not a build. Developers can ship updates without a post, or post about several updates at once.
• Untagged posts are recognised from their words, so a few updates are missed and a few other posts may be counted. Tagged posts are marked Patch notes on the Updates tab; recognised ones are marked Update.
• Older posts are being read back through each game's history, most played games first, so months before October 2026 fill in over the coming days.

Source: Steam Web API, ISteamNews/GetNewsForApp. Full methodology