Post
Topic
Board Pools
Re: [8500 GH/s] Slush's Pool (mining.bitcoin.cz); TX FEES + UserDiff; ASIC tested
by
organofcorti
on 30/04/2013, 12:35:23 UTC

Probably shouldn't comment since I haven't had a chance to read those yet, but I did mention above about how I thought the system was outdated.
Judging by the hash rates in the top of those they aren't very recent.
If im wrong, please dont hang me! I'll apologise for my ignorance once I have had time to look at things properly.

4.2 and 4.3 are the important ones - 4.1 is just background. They are from last year, but the score method is the same now as it was then.

Very good read indeed. I wonder how many of the forum members will take the time to read & understand (!) it. I see a rather wide spectrum of skills and attitude and many reoccurring questions that makes me assume the majority will just skip anything longer than a few paragraphs. Anyway, congratulations, I really recognize the full worth of these quality articles.

Cheers,
   T


Yes I found those the other day and thought they were excellent as well.  (When is the next one coming out?)

I kept seeing blocks that had under-calculated (by a lot) and it was bugging me until I found those.

The TL;DR version is that in order to prevent pool hopping Slush's scoring mechanism rewards shares found later in the round more than shares found earlier in the round.  This mechanism as implemented also introduces variance in the pay out.  Sometimes you get more than expected for a block and sometimes you get less as compared to a purely proportional payout system.  To check, look at your highest and lowest rewards over time and you should find some lower and some higher than the value calculated by this formula: (Block Value * 0.98 * your shares) / total shares

If you are a full-time miner however, the long term effect of the variance will disappear and your long term reward will look almost identical to what it would if that formula above were actually being used.  The end result is that pool hopping from Slush's pool is only profitable to a very, very tiny degree and full time miners are not losing much reward to pool hoppers. 

Slush could lower that pool hopping profitability even more but it would raise the payout variance even more which would make some blocks look even worse.


Well, TiborB,  there's you answer - not.you read them and understood them Smiley

Good job understanding and explaining in simple terms what the effects of Slush's score method is. It is exploitable, although the possible cost to miners is minimal, and no-one is pool hopping anymore anyway. Slush's score was why this pool was my favourite for so long. The basic idea is simple, as not.you has explained, but it had hidden complexities that were waiting to be discovered. It's a great proving ground for your mathematical abilities, and without Meni Rosenfeld's help I would have fallen in battle.

As for when the next one is coming out ... um, I kind of lost track of time. Since there's so much interest in the pool atm, I'll get started on it.