Validator permits

To count as a validator on a subnet, a neuron needs a validator permit. The chain hands these out again every epoch to the neurons with the most stake behind them, up to a cap that is 128 by default and can differ by subnet. A minimum amount of stake also applies.

If a validator slips out of that group, its scores are ignored and it earns no dividends. The stakers behind it lose their share of those dividends too.

A permit alone is not enough. A validator that stops submitting scores for too long is also left out.

For a staker, this makes a validator's stake and activity worth checking. A validator close to the cutoff can lose its permit when other neurons gain stake, and the stake behind it stops earning until it qualifies again.