Checkmate

It means the king is under direct attack and cannot avoid being captured.
There are situations where you want to checkmate someone. May be in debate or discussions or game but I find checkmate principle useful for the bugs that I would raise against the Software.
I ask below questions before raising a bug

1. Why do you think it is a bug?
2. Are you reporting symptom or real problem?
3. What supporting facts would help to justify reasons of declaring a bug?
4. Is it reproducible?
5. Reproducible steps are clear enough to help others to replicate?
6. Is bug description provides clarity on bug and its consequences being present in application?
7. Do you need to attach other reference document or screenshots?
8. Are you attaching appropriate screenshots?

I would also check certain things before raising a bug

1. If bug is already raised in bug tracking system?
2. Are you giving enough justification while deciding the severity of a bug?
3. Is it environmental, build, data or application related issue? Categorising bug would help us to get clear idea about bug.
4. Are you working on the latest build?
5. Is your test data valid and not expired?
6. Is testing function of application still in development?
7. Do you really understand the functionality under test?

I think tester’s effectiveness would be counted on helping developer to fix bugs rapidly.
I think the tester should apply the checkmate principle to avoid rejections for raised bug.
As we know we spend lot of efforts and time on finding bugs then it make lot of sense to avoid rejections that are the whole point.