RPS game based on nested vectors. Written in Clojure

rps.clj

(defn rpswinner
  [match]
  (if (= ((match 0) 1) ((match 1) 1))
    (match 0)
    (if (and (= ((match 0) 1) "R") (= ((match 1) 1) "P"))
      (match 1)
      (if (and (= ((match 0) 1) "P") (= ((match 1) 1) "S"))
        (match 1)
        (if (and (= ((match 0) 1) "S") (= ((match 1) 1) "R"))
          (match 1)
          (match 0)
        )
      )
    )
  )
)

(defn rpstournament
  [tournament]
  (if (instance? String (tournament 0))
    tournament
    (rpswinner (vector (rpstournament (tournament 0)) (rpstournament (tournament 1))))
  )
)

(println (rpstournament 
  [
    [
        [ ["Player1", "P"] ["Player2", "S"] ]
        [ ["Player3", "R"] ["Player4", "S"] ]
    ]
    [
        [ ["Player5", "S"] ["Player6", "P"] ]
        [ ["Player7", "R"] ["Player8", "P"] ]
    ]
  ]
))