To easily adjust the ratio of a case where a ball is involved with a pinwheel to a case where the ball is not involved with the pinwheel.

With the enlargement of a performance display part, a clearance between the left side of a center decoration 18 and a guide rail 8 is formed with a guide face 29 formed into an arcuate shape recessed from the left side to the right side in the left side face of a partition wall 23 of the center decoration 18, a pair of guide pin groups 33 for the pinwheel 19, and a continuous pin group 34 for the pinwheel 19. This constitution can facilitate adjusting the ratio of the case where a ball released from the guide face 29 toward a clearance D2 between the left-side guide pin group 33 and the continuous pin group 34 is involved with the pinwheel 19 to a case of non-involved with the pinwheel 19 by adjusting two pins, or the uppermost pin of the left-side guide pin group and the lowest pin of the continuous pin group 34 to narrow or widen the clearance D2.