What's the difference between RSMPPS and CPPSRB?

[grue]

http://eligius.st/wiki/index.php/Shared_Maximum_PPS
http://eligius.st/wiki/index.php/Capped_PPS_with_Recent_Backpay

they both pay the most recent shares first.

[redtwitz]

With RSMPPS, the pool pays the shares in the current round first (and underpays them if there aren't sufficient funds), then the shares of the previous rounds (prioritizing recent rounds). This makes the reward method hoppable, since mining in long rounds will result in partial/delayed payment of the submitted shares.

With CPPSRB, the pool pays as much shares as it can every time a block is found, prioritizing recent shares. Since the probability of finding a block is always the same (no matter how long the current round is), this reward method provides protection against pool hopping.

[grue]

So the only difference is that CPPSRB rewards are distributed by share, and RSMPPS are distributed by round?

[redtwitz]

Yes. If this difference is significant or not depends on the miners' behavior.

Consider a 50M shares round at 25M difficulty. With RSMPPS, all shares will be paid 50 satoshis each. In contrast, with CPPSRB, the 25M most recent shares will be paid 100 satoshis each. If all miner mined continuously during the round, there will be practically no difference.

However, after the first 25M shares have been submitted, a smart/dishonest miner would stop mining at the pool since he's guaranteed to receive only a part of the PPS rate for all shares (existent and future) in the round. With CPPSRB, there is no incentive to switch pools, since he will still get paid full for the future shares if the round ends after 50M or less shares.