Funny enough, optimizing for promotion is not only a common strategy among individual contributors but is also encourage by mgmt. During my single year at Google I collaborated with a guy from a different team. His strategy was to do most of the meaningful (measureable) work on his own. Fair enough, I don't care. But he didn't predict that the project can be reassign. At that was exactly what happened. When I ask product manager why, he said that this is normal practice, credits should go to the product owning team. When discussed such situations with other googlers two separate views emerge: either you're new and you exploit the system as is or "It's not the same google any more". Funny fact that we still think about that old google when it comes to culture, work, ppl, etc.