(define (check p) (< (random) p))
(define singlebronze 0)
(define tenbronze 0)
(define silvers 0)
(define golds 0)
(define (pin r c) (cond
                    ((= r 1) (pin 2 (if (check 0.5) c (+ c 1))))
                    ((= r 2) (pin 3 (if (check 0.5) c (+ c 1))))
                    ((= r 3) (cond
                               ((or (= c 1) (= c 6)) (pin 4 (if (= c 1) 1 5)))
                               ((not (or (= c 2) (= c 5))) (pin 4 (if (check 0.5) c (- c 1))))
                               ((check 0.25) (pin 4 (+ (if (= c 2) 3 4) (if (check 0.5) 0 1)))) ;wheel succeeds
                               (else (pin 4 (if (check 0.5) c (- c 1))))))
                    ((= r 4) (pin 5 (if (check 0.5) c (+ c 1))))
                    ((= r 5) (cond
                               ((= c 1) (pin 6 1))
                               ((= c 6) (pin 6 5))
                               (else (pin 6 (if (check 0.5) c (- c 1))))))
                    (( = r 6) (cond
                                ((or (= c 2) (= c 4)) (begin (set! singlebronze (+ 1 singlebronze)) 'single))
                                ((= c 3) (if (check 0.25) (begin (set! silvers (+ 1 silvers)) 'silver) 'drain))
                                (else (pin 7 (if (check 0.5) c (+ c 1))))))
                    ((= r 7) (cond
                               ((or (= c 1) (= c 6)) (pin 8 (if (= c 1) 1 5)))
                               ((or (= c 2) (= c 5)) (if (check 0.25) (pin 8 (- (if (= c 2) 3 4) (if (check 0.5) 0 1))) (pin 8 (- c (if (check 0.5) 0 1)))))
                               (else 'TILT)))
                    ((= r 8) (cond
                               ((or (= c 1) (= c 5)) (begin (set! singlebronze (+ 1 singlebronze)) 'single))
                               ((or (= c 2) (= c 4)) (begin (set! tenbronze (+ 1 tenbronze)) 'ten))
                               ((check 0.1) (begin (set! golds (+ 1 golds)) 'gold))
                               (else 'drain)))))

(define (run-a-million-tests)
  (begin
    (set! singlebronze 0)
    (set! tenbronze 0)
    (set! silvers 0)
    (set! golds 0)
    (build-list 1000000 (lambda (x) (pin 1 1)))
    `((,singlebronze singles) (,tenbronze tens) (,silvers sets of silvers) (,golds sets of golds))))
(run-a-million-tests)