Thresholds for verification/checkpoints/rewards.

[kayabaNerve]

Verifying a transaction requires 81% of Merit. A checkpoint requires 51% of Merit. Earning rewards for a transaction requires it gets 51% of Merit.

All three of these values should use a 67% threshold. The desync between Merit needed for verification/rewards is due to the risk of double spends (which can be split 60/40) with a lack of certainty about finalization. That said, due to there's not too much value in defining a distinct threshold when we already can't use the Verifications in real time.

As for checkpoints, the statement stands.