[ Admittedly, such variables as corner kicks are not so actively monitored as vital match outcomes. Nonetheless, when the of these aspects are put together in a two sided system, they pose various financial risks to the concerned parties. The practise of paying attention to the things that seem unusual in the field assists us in modifying our good sense and will not allow us to become victims of malicious mindsets.
Well it's easier to manipulate some games than others. Soccer depends more on team effort and performance unlike games like tennis, boxing and many others where the outcome of the bets depend on only one person that way it's very easy to manipulate. In a boxing match for instance a player can choose to lose on purpose.
It might not be with a KO obviously because it's painful but points can make that happen if it's a friendly match it's even way feasible.