Quote from: hendra147 on May 20, 2015, 08:53:50 AM

Where you get that stats ?
hemmm mining like a gambling game

https://www.btcguild.com/index.php?page=pplns
More general infos about profitability can be found here:
http://organofcorti.blogspot.it/2015/05/may-17th-2015-mining-pool-statistics.html

When you gamble you know who's statistically going to win: the gambling house. Now, probably the best side of the cryptocurrencies is that there is no central bank to play the gambling house's role (or to call the cards anyway) ... that's why one wonders why many PPLNS pools average luck is so ofter quite below from 100%. As eleuthria pointed out, orphaned blocks can explain it partially. It doens't clarify (to me at least) how can big PPS pools stay alive...But I'm new to this world, and I have some naivety to wear off.