• Variables: C = 300
• Simple scoring system: exp(round_time / C)
• Pays full reward for every block for work on that same block
• Pays in excess of work done for short blocks
• Pays less than work done for old shares
• Weighs shares by time submitted
• Slight benefit possible with strong pool hopping skills
• Risk from withholding is distributed among miners

• Easy math: (your shares / total shares) * reward
• Pays full reward for every block for work on that same block
• Pays in excess of work done for short blocks
• Pays less than work done for long blocks
• Easy payout improvement with pool hopping
• Risk from withholding is distributed among miners

• Fixed rate of payout for work performed, limited by actual miner performance
• Never overpaid based on pool earnings; underpaid only when work performed has failed to deliver
• No benefit for pool hopping
• Risk from withholding is distributed among miners
• Non-reward credits carry over for future work

• Fixed rate of payout for work performed
• Never over or underpaid based on pool earnings
• High risk for operator that pool might not earn as much as it pays out
• Absolutely no variability
• No benefit from pool hopping
• Risk from withholding is carried entirely by pool operator

• Variables: N = difficulty * 2
• Easy math: (your shares / N shares) * reward
• Pays full reward for every block for work on that same block
• Pays in excess of past work done for most blocks
• Doesn't pay some shares at all for excessively long blocks
• No benefit from pool hopping
• Risk from withholding is distributed among miners