That really depends on the pool; Eligius pays everything. Maybe OP doesn't know about pooled mining?
True, but the current block generation fees it really makes no odds whether a pool shares them with the miners or keeps them. I do agree that every little bit helps, but at about 0.01% that is still only 1 extra Bitcoin for every 100ish blocks generated.
I suspect that the Original Poster does not fully understand how mining works.
(took me a second to work out what OP stood for)
Maybe an example would help.
At current difficulty of 1777774.482
@ 1Ghash/second (solo mining) you would probably find a block once every 88 days, 8 hours, 59 minutes (on average)
@ 10Ghash/second (solo mining) you would probably find a block once every 8 days, 20 hours, 5 minutes (on average)
@ 100Ghash/second (solo mining) you would probably find a block once every 21 hours, 12 minutes (on average)
Note the magical words above "average" and "probably". Lets take the 10Ghash/second rate of searching for a nonce to generate blocks.
So the average is 8 days, 20 hours, 5 minutes, but this is all statistics so you will have a 50% chance of finding the nonce to solve the block after 6 days, 3 hours, 0 minutes, and a 95% chance of solving a block after 26 days, 11 hours, 23 minutes. It is all down to luck and statistics. The reason why almost everyone joins a pool these days is because a pool smooths out the rough patches. Solo mining you could be really unlucky and the first few blocks you find will take 26+ days each to find, or you could be dating lady luck and the first few blocks take less than a day each to find.
On average at 10Ghash/second (at current difficulty) you will in the long term find blocks at the average rate of one block every 8 days, 20 hours, 5 minutes.
Joining a pool increasing the hashing power so the pool will find blocks faster, but not faster than the combined rate of all it's miners. If the pool consisted of 3 miners one at 1Gh/sec, one at 100Gh/sec and you at 10Gh/sec the combined rate (at the current difficulty of 1777774.482) of 111Gh/sec would one average generate a new block every 19 hours, 6 minutes.
But statistics are still at play so there is a 50% change of find a block after only 13 hours, 14 minutes and a 95% chance of finding a block after 2 days, 9 hours, 14 minutes.
There is no magic involved you mining at 10Gh/sec will still end up with, on average, 50 BTC after 8 days, 20 hours, 5 minutes.
The pool in total, on average, should have mined 555 BTC after 8 days, 20 hours, 5 minutes.
500 going to the 100Gh/sec miner (10 times more hashing power than you).
50 going to you mining at 10Gh/sec and
5 going to the 10Gh/sec miner. (10 times less hashing power than you).
There are only two ways for the amount of bitcoins you receive to increase. One is for you to add more hashing power, the other is for the difficulty to decrease. It has been trickling down over the last few difficulty re-evaluations. And it is predicted to decrease at the next difficulty adjustment in 94 blocks time to about 1750233. But that is not going to increase your possible income by any significant amount.
Date and time block# 256 Bits Difficulty Days %difficulty change (increase or decrease)
------------------- ------- -------- -------------- ---- ------
2009-01-03 18:15:05 0 1d00ffff 1.000000 0.0 0.00
2009-01-27 13:38:51 2016 1d00ffff 1.000000 23.8 0.00
2009-02-12 19:16:30 4032 1d00ffff 1.000000 16.2 0.00
... snip ...
2011-05-26 18:41:56 127008 1a269421 434877.045527 7.9 78.15
2011-06-06 12:25:05 129024 1a1d932f 567269.530162 10.7 30.44
2011-06-15 13:49:34 131040 1a132185 876954.493513 9.1 54.59
2011-06-24 11:45:23 133056 1a0c2a12 1379192.288228 8.9 57.27
2011-07-06 20:35:46 135072 1a0abbcf 1563027.996116 12.4 13.33
2011-07-19 19:23:09 137088 1a09ec04 1690895.803052 12.9 8.18
2011-08-01 08:11:19 139104 1a08e1e5 1888786.705353 12.5 11.70
2011-08-15 23:44:54 141120 1a094a86 1805700.836193 14.6 -4.40
2011-08-30 05:15:03 143136 1a096fe3 1777774.482001 14.2 -1.55
Pool mining, solo mining or a group of friends buying hardware will not increase your average generated BTC's, It is purely based on your hashing power and the difficulty. The difficulty is adjusted up/down every 2016 blocks generated, circa every two weeks, to match available hashing power to try and keep the new block generation rate on average once every 10 minutes. So as more hashing power joins the Bitcoin network the difficulty increases, and if hashing power leaves the difficulty will be reduced.