Except the algorithm being gamed can change suddenly, drastically and without the gamer's knowledge.

When such changes occur, the gamer will be docked until they can reverse-engineer the new algorithm. There's also the risk that all their previous inputs "gaming" the system might be reconsumed to terrible results as well, effectively rewriting their historical performance disasterously.

As always, those with the social standing and power to have insider knowledge or guidance will be in the best position to profit off such systems.