on its merits

on (someone's or something's) (own) merits

Objectively based on or due to someone's or something's actual qualities, actions, etc. (as opposed to other, less objective factors). I can assure you that she got the job on her own merits and not because she is the CEO's daughter.
See also: merit, on
Farlex Dictionary of Idioms.

on its merits

Also, on one's merits or according to one's merits . With regard only to the intrinsic quality of something or someone. For example, Who supports it doesn't matter; we have to consider the idea solely on its merits, or The agency doesn't care about her references but wants to hire candidates according to their merits . [Late 1800s]
See also: merit, on
The American Heritage® Dictionary of Idioms by Christine Ammer.
See also:
  • on (someone's or something's) (own) merits
  • reflect on (someone or something)
  • reflect well, badly, etc. on somebody/something
  • on present form
  • sold on (something)
  • sold on someone or something
  • ragged
  • a ragged colt may make a good horse
  • colt
  • a track record