Bitcoin Forum

Guys... these are the current luck stats of a big pool.
/ 75.645% / 91.791% / 88.821% / 93.131% /
 3D / 1W / 2W / 1M / 3M
C'mon... luck goin up and down and always rounding near 99% ? Do you have an idea of why this is happening, really?

It's a thing called variance.  Smaller pools, BTC Guild is hardly a "big pool" these days, have allot of variance in which it has spells of really good luck and solves allot of blocks quickly.  Win, win.  But when it has bad luck it is allot more noticeable.  You need to average over longer period of time.

Any way, everybody PLEASE post in the appropriate thread.  BTC Guild has it's own thread and eleuthria will answer questions like this and has, even recently.  Also us BTC Guild miners will answer you too.  There is no need to keep creating new threads and filling up the forums with duplicate subjects.
Thanks,
Sam

Thank you Sam for your reply and please forgive me if my post wasn't appropriate.
I know eleuthria by fame and I didn't want to point -directly or indirectly- any accusations at BTCguild (I actually avoided to cite it).  Moreover, that behavior may be common to other pools, so I'm interested in why the luck seems so low even in the long run; BTC Guild probably is just showing more stats.

BTC Guild is not even 5% of the network any more.  The only pools larger than 5% these days are Chinese (and private farms).  It is possible and has happened a few times where a single bad block for BTC Guild now takes over 24 hours to complete.  Back when we were 35-40% of the network, that same block would have only taken 3-4 hours. 

This absolutely nukes the luck figures for the 1D/3D/1W/2W, and even has a big impact on the 1-month luck, due to how small we are now.  Our 1D-1M figures were over 100% until that bad block hit, and 3M was climbing back up as well.  But at this size, you will almost never see 98-102%.  Luck "averages out" in an infinite time frame, but when you're small, it rarely IS at the average, it will be one extreme or another, and when you average the extremes you'll probably get close to neutral.

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.

They can't, not indefinitely anyway.  All PPS pools either go bankrupt or change their payout method to stay viable.  It has happened over and over.  The same will eventually happen to f2pool too.

It's a reason why PPS pools charge a fee to miners - to try and help offset the statistical variance the pool is subject to.  I'm pretty sure I read a post on here not too long ago that gave the odds... and those odds are pretty dismal looking if you're a pool owner.  Something like you needed to have at least 1500BTC in a reserve to have a tiny chance of avoiding going broke if you're a PPS pool charging 5% fees.

Ahh... here's that post: https://bitcointalk.org/index.php?topic=854368.msg11149806#msg11149806

The referenced paper by Meni in that post is a great read.