Why is number of accepted and rejected shares different on minerstat and on pool?

The main difference is the way the shares are tracked, just like the hashrate shown on minerstat is reported by the miner, and not "average" or "current", which are calculated based on the amount of shares submitted, the number of shares shown as accepted or rejected on minerstat is what the mining client reports. You can read more about difference in hashrate reported on minerstat and on pool in this article.

Let's explore the ways amounts of accepted and rejected shares are calculated on minerstat and on pools in more detail below.

On minerstat, the way we track the number of accepted and rejected shares is by checking what the mining client reports.

For instance, if the client's been started 12 hours ago, the number of shares displayed on minerstat will be quite large, as it's a summary of all the shares found in those 12 hours. However, if you have just restarted the client, the number of accepted shares might be very low, or even 0, as the client has found very little amount of shares (or even none, in case of 0 being displayed).

The miner reporting 0 accepted and 0 rejected shares right after its restart is also what's causing the 0% efficiency being displayed. However, if the config is correct, and you're mining successfully, for a short period of time that is nothing to worry about - the miner will find a share, submit it, and report as accepted (or rejected) which will then affect the efficiency shown. You can read more about mining efficiency in this article.

Pools track the number of accepted and reject shares different to mining clients (and minerstat, as a result of that), and each pool has their preferred way of tracking these amounts.

As an example, Ethermine, one of the most popular ETC pools, reports the number of accepted, stale or rejected shares in the last hour. Ezil, another popular pool which we partner with, calculates and shows the average and current hashrates with the average including data for the last 3 hours.

Binance Pool doesn't display the number of accepted and rejected shares at all, instead displaying the approximate hashrate calculated from shares and a percentage value of rejects it received.