system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: Microsoft's stack employee ranking system

With the recent news of Ballmer being out of Microsoft, there is a lot of talk about how the the stack ranking system he implanted was a wrong move, and was one of the reasons he was forced out.  
I couldn't find anything that explains simply what this system is and why was it bad, so I hope you guys can help.
gpt
Let's say you and nine friends get together to go pick berries for the local baker to make pies with. When you bring the berries to the baker, the baker doesn't want to give everyone the same payment, since it's not fair to pay someone who picked less berries the same as someone who picked more berries. The baker says that one of you has to be the worst, two of you are below average, four of you are average, two of you are above average, and one of you is the best. The person who is the worst gets nothing and is never allowed to pick berries again. The two below average people get $5 and if they don't do better during the next berry picking trip, they won't be allowed to pick berries again after that. The four average people get $10 and are allowed to pick berries again. The two above average people get $20 and are allowed to pick berries again. They are also entered in a random drawing that would allow them to pick a different kind of berries, which would pay twice as much. The best person gets $40 and automatically gets to pick the better berries the next time.

This seems fair, however every group that picks berries from the original berry patch gets the same reward structure, whether they bring back 100 berries or 10,000 berries. The reward structure also applies even if the work done isn't evenly distributed. For example, if 7 people pick 30 berries each and three people pick 300 berries, only one of the 300-berry pickers gets the $40 and the automatic berry patch upgrade even though all three picked the same amount. The same applies if all ten pick 1000 berries, one gets the big reward, one gets nothing and is asked to leave, everyone else gets something in the middle.

There is no incentive for the best berry pickers to work in the same group and do outstanding work. There *is* an incentive to make sure that everyone you work in a group with is worse than you, even if that means crushing the berries they pick, accidentally misplacing their berry baskets, or lying about how many berries they picked.