The winning story was written by SF author John Sladek (though I see he also wrote a couple mystery novels starring the sleuth in this story). Like many of the stories in the collection, he's pulling out all the stops to get noticed. I cottoned onto the correct detail, but didn't come to quite the right solution of the mystery.
John Garforth's "A Quite Conventional Death" is amusing, set as it is at a convention of mystery writers. The mystery is fine, but the juicy scandals and personality clashes among the authors are the more enjoyable elements.
I think the nadir is reached in the story where the murder is committed via a scientific invention that is patently ridiculous.
I'm not a huge mystery buff, but these were fine to pass the time with.