The one exception to that is hash rental companies such as NiceHash and MRR et al. They have in the past (several years ago) been accused of withholding blocks pointed at specific pools. Reasons were never hashed out (pun) but general opinion was to try and break the target pools as favors to some large players. Rental companies get paid no matter what so it did not hurt them. Then maybe 8 years ago there was the unintentional block withholding by Genesis mining who were using Slush. They had a massive hashrate and when other Slush users hit a block Genesis got paid per their hash rate. One problem: Genesis was using a proxy to combine all their miners into one connection and after a faulty update that proxy had a bug in it which caused it to ignore all blocks found and not report them. This went on for several weeks. Somewhere in the SlushPool thread there is a long series of posts about it dealing with Slush's apparent incredibly long streak of "Bad Luck". Methinks it was Kano that pointed out the problem to Slush who then did some digging through their logs to reveal that yes, during that time even when taking variance into account, statistically Genesis should have found many blocks and yet had found zero. Timing of Slush's drop in Luck matched to when Genesis's proxy was updated. Slush bitched at Genesis (who fixed the bug) but never returned any of the 33win 80 to the Slush users who lost out on earnings that Genesis got for doing useless work. With Genesis at the time being something like 1/4 of Slush's hash rate that was a rather large amount.
The one exception to that is hash rental companies such as NiceHash and MRR et al. They have in the past (several years ago) been accused of withholding blocks pointed at specific pools. Reasons were never hashed out (pun) but general opinion was to try and break the target pools as favors to some large players. Rental companies get paid no matter what so it did not hurt them. Then maybe 8 years ago there was the unintentional block withholding by Genesis mining who were using Slush. They had a massive hashrate and when other Slush users hit a block Genesis got paid per their hash rate. One problem: Genesis was using a proxy to combine all their miners into one connection and after a faulty update that proxy had a bug in it which caused it to ignore all blocks found and not report them. This went on for several weeks. Somewhere in the SlushPool thread there is a long series of posts about it dealing with Slush's apparent incredibly long streak of "Bad Luck". Methinks it was Kano that pointed out the problem to Slush who then did some digging through their logs to reveal that yes, during that time even when taking variance into account, statistically Genesis should have found many blocks and yet had found zero. Timing of Slush's drop in Luck matched to when Genesis's proxy was updated. Slush bitched at Genesis (who fixed the bug) but never returned any of the 33win 80 to the Slush users who lost out on earnings that Genesis got for doing useless work. With Genesis at the time being something like 1/4 of Slush's hash rate that was a rather large amount.

The one exception to that is hash rental companies such as NiceHash and MRR et al. They have in the past (several years ago) been accused of withholding blocks pointed at specific pools. Reasons were never hashed out (pun) but general opinion was to try and break the target pools as favors to some large players. Rental companies get paid no matter what so it did not hurt them. Then maybe 8 years ago there was the unintentional block withholding by Genesis mining who were using Slush. They had a massive hashrate and when other Slush users hit a block Genesis got paid per their hash rate. One problem: Genesis was using a proxy to combine all their miners into one connection and after a faulty update that proxy had a bug in it which caused it to ignore all blocks found and not report them. This went on for several weeks. Somewhere in the SlushPool thread there is a long series of posts about it dealing with Slush's apparent incredibly long streak of "Bad Luck". Methinks it was Kano that pointed out the problem to Slush who then did some digging through their logs to reveal that yes, during that time even when taking variance into account, statistically Genesis should have found many blocks and yet had found zero. Timing of Slush's drop in Luck matched to when Genesis's proxy was updated. Slush bitched at Genesis (who fixed the bug) but never returned any of the 33win 80 to the Slush users who lost out on earnings that Genesis got for doing useless work. With Genesis at the time being something like 1/4 of Slush's hash rate that was a rather large amount.

The one exception to that is hash rental companies such as NiceHash and MRR et al. They have in the past (several years ago) been accused of withholding blocks pointed at specific pools. Reasons were never hashed out (pun) but general opinion was to try and break the target pools as favors to some large players. Rental companies get paid no matter what so it did not hurt them. Then maybe 8 years ago there was the unintentional block withholding by Genesis mining who were using Slush. They had a massive hashrate and when other Slush users hit a block Genesis got paid per their hash rate. One problem: Genesis was using a proxy to combine all their miners into one connection and after a faulty update that proxy had a bug in it which caused it to ignore all blocks found and not report them. This went on for several weeks. Somewhere in the SlushPool thread there is a long series of posts about it dealing with Slush's apparent incredibly long streak of "Bad Luck". Methinks it was Kano that pointed out the problem to Slush who then did some digging through their logs to reveal that yes, during that time even when taking variance into account, statistically Genesis should have found many blocks and yet had found zero. Timing of Slush's drop in Luck matched to when Genesis's proxy was updated. Slush bitched at Genesis (who fixed the bug) but never returned any of the 33win 80 to the Slush users who lost out on earnings that Genesis got for doing useless work. With Genesis at the time being something like 1/4 of Slush's hash rate that was a rather large amount.