Only the real time.
Nothing else.

To challenge a record, you upload the file of a run you've already recorded: GPX, FIT or TCX, exported from your watch or any running app. The time that counts is the one your device recorded. You never type in a time by hand.

We check that the file has a real, timed GPS track, that it's a run and not a ride or a walk, that no stretch is faster than a runner can hold, that the distance stored by the device matches its GPS track, and that the distance is at least 99% of the target and at most 5% over it: 4.95–5.25 km for a 5K. Running further is allowed because it only costs you time: what counts is the total elapsed time of the whole run, pauses included.

What a file can't prove, honestly: who was wearing the watch. A carefully forged file can pass these checks, which is why every record says it was verified from the GPS file. We never keep your GPS track, which would reveal where you live and train; only a fingerprint of each run, so the same run can't be used twice.

If your verified time is lower than the current holder's, the baton passes to you the moment verification closes. The distance card shows your name, your city and your time, and the previous holder moves down into the history.

There are no ties to settle behind closed doors: on an equal time, the baton stays with whoever already held it. The only other rule applies to the very first claim of each distance, which has to beat a qualifying time, so a record can't start as a walk.

Every handoff is linked to the one before it in a hash chain, so the latest link commits to the whole history. Right after a handoff, that link is anchored on a public blockchain. From then on no one, not even us, can quietly delete or alter an anchored handoff: the chain would no longer match.

Runchain anchors on Bitcoin through OpenTimestamps, a free, open timestamping service: our hash is combined with many others into a single Bitcoin transaction. Confirmation usually takes a few hours; until then the handoff shows “Anchoring pending”. It's already valid and saved, just not sealed yet.

Every anchored handoff links to its proof file (.ots). Anyone can check it with the OpenTimestamps tools against the hash of the history, which you can recompute from the public list of handoffs.

Runchain doesn't hand out points, streaks or badges for taking part. There's no ranking of who “tried the hardest”. For each distance there's only one thing that matters: the fastest time, and who holds it right now.

Five distances, five holders. Everything else is noise.