Bitminter - no rewards when more work was done? Very new to this concept, why would something like this occur on Bitminter's pool?


Completed   Duration    Difficulty  Pay/Hour at 1 TH/s  Total Thps  Your Ghps Your work
2014-10-25 15:02    1h 46m  35,985,640,265  being paid now  2,436.1 10.7    15,856
2014-10-25 13:15    2h 15m  35,985,640,265  being paid now  1,896.0 10.9    20,718
2014-10-25 10:59    2h 13m  35,985,640,265  being paid now  1,935.6 10.4    19,340
2014-10-25 08:45    2h 26m  35,985,640,265  being paid now  1,767.4 10.2    20,756
2014-10-25 06:18    2h 30m  35,985,640,265  being paid now  1,721.0 10.3    21,688
2014-10-25 03:48    2h 11m  35,985,640,265  being paid now  1,951.9 10.2    18,872
2014-10-25 01:36    2h 36m  35,985,640,265  being paid now  1,646.6 10.4    22,722
2014-10-24 22:59    2h 35m  35,985,640,265  being paid now  1,653.5 10.2    22,314
2014-10-24 20:23    2h 37m  35,985,640,265  being paid now  1,641.0 10.9    24,036
2014-10-24 17:46    2h 36m  35,985,640,265  being paid now  1,649.8 10.8    23,620
2014-10-24 15:09    2h 35m  35,985,640,265  ?               1,664.1 10.6    22,992
2014-10-24 12:34    2h 37m  35,985,640,265  0.00000000      1,642.0 10.0    21,882
2014-10-24 09:56    2h 36m  35,985,640,265  0.00000000      1,650.2 10.3    22,502
2014-10-24 07:20    2h 29m  35,985,640,265  0.00000000      1,724.3 10.4    21,844
2014-10-24 04:50    2h 09m  35,985,640,265  0.00000000      1,996.7 8.5     15,322
2014-10-24 02:40    2h 34m  35,985,640,265  0.00057673      1,673.0 0.2     432
2014-10-24 00:06    2h 26m  35,985,640,265  0.00057673      1,756.1 0.2     354
2014-10-23 21:38    1h 41m  35,985,640,265  0.00057673      2,544.7 0.2     222
2014-10-23 19:57    1h 34m  35,985,640,265  0.00057673      2,736.5 0.2     212
2014-10-23 18:22    2h 00m  35,985,640,265  0.00057673      2,135.9 0.2     284


In some cases, next to no work was done - and small reward was found. In others, far more was contributed, but the pay is zero.

I ask on the heels of switching from cgminer to bfgminer; could this be the cause? Is the timing otherwise purely circumstantial?

Thanks!
When a block is found the 10 latest shifts get paid. Finding blocks is a random event. Sometimes we find the next block quickly, other times it takes longer.

Sometimes it happens that it takes a lot of work before the next block is found by the pool. With PPLNS what then happens is that some of the work is not paid at all. The opposite happens when many blocks are found in quick succession. The same work gets paid many times and the pay is extremely good. Over time this evens out.

This is the nature of mining. If you were mining solo instead of in a pool the variance would be much greater. You could find a block and get 25 bitcoins after a few seconds. Or it could take you several years.