Weight-setting is the core act a validator performs on Bittensor: periodically scoring every miner
on a subnet and submitting that scoring as an on-chain vector. Everything downstream — who earns
what, whose stake actually matters — runs off the aggregate of those submissions.

## Block production vs. subnet epochs [#block-production-vs-subnet-epochs]

These are two different clocks, easy to conflate:

* **Chain block production** — the whole Bittensor chain produces a new block on a fixed, short
  cadence (seconds). This is global, shared by every subnet.
* **Subnet epoch** — each subnet has its own `tempo` hyperparameter, measured in blocks (360 is a
  common default, but it's per-subnet and governance-adjustable). When a subnet's block count since
  its last epoch reaches `tempo`, that subnet runs its own **Yuma Consensus epoch** — the point
  where accumulated weight submissions actually get turned into emissions.

Weights can be submitted at any point between epochs, but they don't do anything on their own until
the epoch boundary triggers the consensus run that consumes them. A validator that only submits
right before the boundary and one that submits steadily throughout the tempo window can end up
contributing identically, as long as both submissions are fresh enough — see `weights_rate_limit`
below for the constraint on how often submission is even allowed.

## What happens at an epoch boundary [#what-happens-at-an-epoch-boundary]

Source: `pallets/subtensor/src/epoch/run_epoch.rs`.

1. **Bonds update.** Each validator holds a "bond" toward each miner, which moves toward alignment
   with the *consensus-weighted* view across all validators — not toward any single validator's own
   opinion. A validator whose weights consistently agree with where other high-stake validators land
   builds bonds that track consensus; one that diverges builds weaker bonds. This is the mechanism
   that rewards genuine independent evaluation converging with the group, rather than either pure
   copying or pure divergence.
2. **Incentive is computed per miner** from the consensus-weighted score across all validators'
   submitted weights — a rank/softmax-style computation, not a simple average, tuned by the `kappa`
   hyperparameter.
3. **Dividends are computed per validator** from that validator's bonds combined with its
   [stake-weight](/docs/protocol/stake-weight) (used here as `active_stake`) — not from weights
   submitted alone. A validator with strong bonds but negligible stake-weight, or strong stake-weight
   but no meaningful bonds (never submitted fresh weights), earns correspondingly little.
4. **`combined_emission = incentive + dividends`, computed per neuron, not as a fixed split of one
   pool.** These aren't two halves of a subnet's emission divided by role — a UID's incentive and
   dividend components are each independently derived from that UID's own miner-side and
   validator-side activity respectively. A UID that's both a miner and a validator on subnets that
   allow it earns from both terms; a pure-miner UID's dividend term is simply zero, and vice versa.

## Why staleness matters [#why-staleness-matters]

A validator's `last_update` — the block of its most recent successful weight submission — factoring
against the subnet's `weights_rate_limit` determines whether that validator's submission is
considered current for a given epoch run. Weights that have gone stale (not resubmitted within the
subnet's rate-limit window) don't meaningfully contribute at the next epoch boundary — a permitted
validator sitting on old weights is, from the reward mechanism's perspective, functionally similar
to one that never submits at all. Holding a [validator permit](/docs/protocol/registration-and-permits)
is necessary but not sufficient — the dividend term only materializes from genuinely current,
regularly-refreshed weight submissions.

<Callout title="Permit ≠ earning">
  A validator can hold a permit indefinitely without submitting weights — nothing revokes the permit
  for inactivity by itself, since permit assignment is purely stake-rank based (see [registration
  and permits](/docs/protocol/registration-and-permits)). But an inactive permit holder's dividend
  term stays at or near zero the entire time, since dividends are earned from bonds built by
  actually submitting current weights, not from holding the seat.
</Callout>