How do we count stale shares?

One of the parameters that has a direct impact on the miner’s profitability is the shares calculation method. Which is the way pool treats shares sent by the miner. Most of the pools have 4 types of shares. Apart from accepted and rejected shares that are pretty self explanatory there are two other types of shares — invalid and stale. This is where new miners usually get confused. So we will explain both types:
  • Stale shares are those sent to solve a previous block (this is valid for Ethereum/EthereumClassic). They can still get a portion of a block reward but that will be the so-called uncle block with reduced reward (significantly reduced if talk about ETC). Please note that Zilliqa pool does not have stale shares at all.
  • Invalid shares are those that failed PoW verification and cannot contribute to solving the block.

Obviously miners do not participate in rewards distribution if they send invalid shares. As for the stale shares most of the mining pools (incl. Ethermine and others) treat them as semi-valid with 0.7 coefficient (presuming that 1 is for accepted share). Previously Ezil pool treated both accepted and stale shares as equal with the same 1 coefficient.

Starting from March 4, 2021 we will be introducing a new shares calculation system to ensure a better rewards distribution. We believe this would be fair to give slightly bigger rewards (0.35–0.9%) to those miners who contribute a bigger percentage of accepted shares to the pool.

This system should encourage miners to improve their hardware, software and internet settings to produce healthier shares. Eventually both pool and miners will benefit from that.

Ezil pool will also be adding new servers to our expanding network to help miners get a better ping signal and therefore reduce the amount of stale shares. Keep an eye on the updates of our server’s list or talk to admins in our support chats.

Now let’s talk numbers, here’s a detailed breakdown of the new coefficients and how they will impact your rewards.

Stale shares rate coefficients:

Please bear in mind that the Ezil pool is currently using PPS+ rewards distribution system for ETH which means that each miner is paid based on the number of shares they contributed to the pool + every miner gets a corresponding proportion of the Tx Fees when a block is found.

For ETC mining we use the PPLNS reward system. This is a proportional system of rewards accrual (not static) that calculates your payments based on the number of shares you submitted during a shift.

Our new system is based on the assumption that stale shares can only mine an uncle block with the reduced reward and 0 txFees.

So these are the coefficients we will be applying:

  • 0.8x for PPS part of your reward since the average reward for the uncle block is 1.6 ETH.
  • 0x for + part of your reward because uncle blocks do not include txFees and thus there’s nothing to distribute to the miners.
  • 0.7x for the hashrate calculation in your account (this is for statistics purposes only and doesn’t affect your mining rewards)

  • 0.1x for PPLNS part of the reward and hashrate calculation in your account. Please note that rewards for the uncle blocks in the ETC network are significantly lower than a full block reward.

ZIL rewards will stay the same as we mentioned earlier Zilliqa network does not have stale shares.

How will the new system affect my rewards?

If you have:
  • 3% stale share rate, you will receive ~0.7% less in ETH rewards
  • 1% stale share rate, you will receive about the same in ETH rewards
  • 0% stale share rate, you will receive ~ 0.35% more in ETH rewards because we will increase the PPS proportion of the reward for those who produce healthy shares.

For ETC numbers would be slightly different:
  • 3% stale share rate, you will receive ~1.8% less in ETC rewards
  • 1% stale share rate, you will receive about the same in ETС rewards
  • 0% stale share rate, you will receive ~ 0.9% more in ETC rewards

Based on our data the average stale share rate of Ezil pool is ~1%. This includes all the miners. As you can see there’s nothing to worry about and the majority of our miners will benefit from the increased rewards. The new coefficients will go live on March 4, 2021. You will be able to see your stale shares rate in your account.
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