Comparison of mining pools
Reward types & explanation:
- CPPSRB - Capped Pay Per Share with Recent Backpay. 
- DGM - Double Geometric Method. A hybrid between PPLNS and Geometric reward types that enables to operator to absorb some of the variance risk. Operator receives portion of payout on short rounds and returns it on longer rounds to normalize payments. 
- ESMPPS - Equalized Shared Maximum Pay Per Share. Like SMPPS, but equalizes payments fairly among all those who are owed. 
- POT - Pay On Target. A high variance PPS variant that pays on the difficulty of work returned to pool rather than the difficulty of work served by pool 
- PPLNS - Pay Per Last N Shares. Similar to proportional, but instead of looking at the number of shares in the round, instead looks at the last N shares, regardless of round boundaries.
- PPLNSG - Pay Per Last N Groups (or shifts). Similar to PPLNS, but shares are grouped into "shifts" which are paid as a whole.
- PPS - Pay Per Share. Each submitted share is worth certain amoutripnt of BC. Since finding a block requires <current difficulty> shares on average, a PPS method with 0% fee would be 25 BTC divided by <current difficulty>. It is risky for pool operators, hence the fee is highest.
- Prop. - Proportional. When block is found, the reward is distributed among all workers proportionally to how much shares each of them has found.
- RSMPPS - Recent Shared Maximum Pay Per Share. Like SMPPS, but system aims to prioritize the most recent miners first. 
- Score - Score based system: a proportional reward, but weighed by time submitted. Each submitted share is worth more in the function of time t since start of current round. For each share score is updated by: score += exp(t/C). This makes later shares worth much more than earlier shares, thus the miner's score quickly diminishes when they stop mining on the pool. Rewards are calculated proportionally to scores (and not to shares). (at slush's pool C=300 seconds, and every hour scores are normalized)
- SMPPS - Shared Maximum Pay Per Share. Like Pay Per Share, but never pays more than the pool earns. 
A statistically valid analysis of some pools and their payout methods: Bitcoin network and pool analysis
|Name||Location||Size||Merged Mining||Reward Type||Transaction fees||PPS Fee||Other Fee||GBT||Launched||Variance||Forum||Website|
|AntPool||China||Large||?||PPLNS & PPS||kept by pool||2.5%||0%||Yes||No||?||?||link||link|
|BitcoinAffiliateNetwork||?||NMC, DOGE||?||kept by pool||?||?||Yes||2014-07-15||User/Dynamic||link||link|
|Slush's pool (mining.bitcoin.cz)||Global||Medium||No||Score||shared||2%||Yes||No||2010-11-27||User||link||link|
|BTCDig||Small||No||DGM||kept by pool||0%||Yes||2013-07-04||User/Dynamic 20SPM||link||link|
|btcmp.com||Small||No||PPS||kept by pool||4%||Yes||2011-06-28||Diff 1||link|
|BW Mining||China||Medium||?||PPLNS & PPS||?||?||?||Yes||?||?||?||link|
|Eclipse Mining Consortium||Global||Small||No||DGM & PPS||kept by pool||5%||0%||Yes||Yes||2011-06-14||User/Dynamic||link||link|
|Eligius||Small||NMC||CPPSRB||shared||0%||Yes||Yes||2011-04-27||Dynamic: 32 shares/m||link||link|
|F2Pool||China||Large||?||PPS||kept by pool||4%||Yes||No||?||?||?||link|
|GHash.IO||Small||NMC, IXC, Devcoin||PPLNS||shared||0%||Yes||No||2013-07-01||User||link||link|
|Give Me COINS||Small||NMC||PPLNS||shared||0%||Yes||Yes||2013-08-12||Dynamic||link||link|
|Merge Mining Pool||Small||NMC, IXC, Devcoin||DGM||shared||1.5%||Yes||No||2012-01-08||User||link||link|
SPV Mining / Old Bitcoin Core
The following pools are known or strongly suspected to be mining on top of blocks before fully validating them with Bitcoin Core 0.9.5 or later. Miners doing this have already lost over $50,000 USD during the 4 July 2015 fork and have created a situation where small numbers of confirmations are much less useful than they normally are.
The following pools are believed to be currently fully validating blocks with Bitcoin Core 0.9.5 or later (0.10.2 or later recommended due to DoS vulnerabilities):
- BTC China (described as SPV mining, but they're performing effective valiation)
- Slush Pool
- Note that pool hashrate is largely irrelevant but can be seen as a popularity measurement. It is a theoretical security issue if one pool gains above 50% of the total computational power of the network, thus consider joining a pool based on other metrics. The pool's total hash rate is very dynamic on most pools. Over time, as the network grows, so does most pool's hash rates. The displayed values are the pool's relative sizes based on the network: Small: less than 2%, Medium: 2%-10% Large: greater than 10% of the network.
- Merged mining allows miners to mine on multiple block chains at the same time with the same hashing.
- The difficulty of the shares can be changed by the user.
- Merged mining can be done on a "solo mining" basis (payouts in the merged chain are not pooled).
- Intention to continue SPV mining, Wang Chun, 4 July 2015
- Pooled mining
- Pool Distribution Summary
- Bitcoin Mining
- Video: What is Bitcoin Mining
- Bitcoin Mining Pools
- Bitcoin Mining Pools Comparison