usage of the might have been/had been

[Rameshreddy]

I request the all the members please explain the correct usage of the might have been/had been

when we use might have been/had been

[Cerberus™]

"Might" introduces an uncertainty, turns a certain fact into a possibility.

- When asked about the murdered girl, the police officer stated: "Before her father came looking for her, she had been playing in the yard. That much is certain from the witness."
(That she was playing in the yard at some point in time is stated as fact.)

- When asked about the murdered girl, the police officer stated: "Before her father came looking for her, she might have been playing in the yard. That is, we found her teddybear there. But she might have left it there the day before."
(That she was playing in the yard is stated as a possibility only: it might not be true.)

"May have been" states a possibility, too; "might have been" is even less probable than "may have been".