If you have a 6970, I'm guessing you have a hashrate of 350 Mhps? Then you're submitting on average 4.88 difficulty 1 shares per minute. At the current pool hashrate of 3500Ghps, 50000 shares will take 61 seconds. Since the number of shares you submit in a given time is a poisson distributed variable, both the mean and the variance of your submissions in 61 seconds = 4.97. Let's round that to 5.
That might not be helpful, but below is a table of probabilities that you will submit a given number of shares in 61 seconds:
0 0.006737947
1 0.033689735
2 0.084224337
3 0.140373896
4 0.175467370
5 0.175467370
6 0.146222808
7 0.104444863
8 0.065278039
9 0.036265577
10 0.018132789
At current difficulty the probability of a round lasting 25000 to 75000 shares is about 0.03. At the current pool hashrate, a block will be solved on average every 32 minutes, or 315 rounds per week. So in a week you'd see 10 rounds between 25000 and 75000 shares.
So you see it's not unlikely, but certainly not usual, that in a week there would be a 50000 share round in which you'd submit no shares.
Thanks a lot for the info. As you can see here, my chances of getting 0 shares for small blocks are around 0.6%. I've been mining here for around 17 days, and got a few 0 share bloks already ...which makes me think I'm special .
I wasn't implying that you can get higher profits. If you read carefully, all I was after is reduced variance. Both variances. Deepbit, you're saying that you have to be lucky to get a share in a small block and in time it averages out anyway. All I'm asking is whether I'll be able to reduce variance by having many accounts, and getting a share in a small block at least with some of those accounts. Since this topic already been discussed earlier, I wont bugger you guys with these questions anymore =) Thanks.
P.S. BTW, I'm using proportional payouts and my hash speed for the last 7 shares reported on account page is quite weird. I get anything from 190Mhs up to 933Mhs per round. My card's speed is stable though, at 362,8Mhs (not overclocked)