PPLNS. Each found block's reward is split across the most recent 100 000 shares, so your cut tracks your recent work - no reward for idle time, no penalty for hopping in. Rewards are credited only when a block matures at 100 confirmations, so orphaned blocks cost you nothing. The pool keeps a 1% fee that funds CypherFaucet - the free faucet that hands out testnet coins so anyone can start mining or testing. Testnet coins have to come from somewhere, so a small slice of what's mined flows back to keep the faucet stocked. Payouts run about every 5.0m: once your balance reaches the minimum it's sent automatically, otherwise it carries forward. A wallet left idle for 30 days has its small leftover balance swept back to the faucet. Round effort (and each found block's luck) is the work done vs. about one block's worth expected - under 100% means a lucky, early block.