no prize for guessing
- (idiomatic) Used to form expressions emphasizing the unsurprising nature of what follows
- You get no prize for guessing what happened when the spider landed on her plate.
This phrase can be used as an interjection:
- The top student was - no prizes for guessing - Sharon.
There seems to be significant use of this phrase that disregards the normal plural agreement of verb and noun:
- There's no prizes for guessing why my mum wasn't happy with that.