Yeah, but anybody with statistical knowledge might have been able to guess that this is a random process and that not evetything is down to individual performan

Yeah, but anybody with statistical knowledge might have been able to guess that this is a random process and that not evetything is down to individual performance. The point of the thought experiment is to make us think of what the system contributes to team/individual performance. In reality every procedd might have a random component, but it might also have a feedback component — e.g. you give a project with many red beats to a team that did well before only to have them (to us: predictably) underperform, then you give it to another team etc. The lesson here is to understand this underperformance doesn't necessarily mean they got worse, it just means they got the harder project to pull off and other teams might have underperformed even more. If you as a manager focus on the totally fictional underperformance of one team vs the other you optimize things that had no bearing on the outcome. In fact you will make things worse as you make yourself believe the (in reality worse) team that only handled red-bead-free projects before will perform better.