reductions is very nice!

Usually, you can replace ocurrences of #(fun %) with just fun!

They take turns attacking each other and when one dies the game ends. In other words: simultaneous deaths cannot happen.

This is not a issue with the kata itself, but with the codewars software. If you are having technical problems with codewars, contact codewars.

Is the Clojure version working?

I get failing "random" tests without any useful debug information, as in:

(= winner (declare-winner a d)) - actual: (not (= "Patrick" "Lew"))

There's also no rule regarding simultaneous deaths, and tests fail if you don't comply with the hidden ordering...

Yes, you're right, the tests helped me out on this one. Should have used sorted-set instead.

Dude, you got lucky on the tests

set has no ordering guarantees