Focusing on the view that the interaction between the "design" of the pachinko machine and the player shapes the experience of playing pachinko, this article discusses some new aspects of players' experiences. It shows that players repeatedly play because the "predictability" of winning attracts them. This is assumed based on the numerical data presented by the pachinko machine manufacturers or the design of data-related presentations around the pachinko machine. This article also focuses on the belief and practice of "Okaruto" which players spontaneously create and find enjoyment with. Finally, it concludes that pachinko players are not only enticed by the seeming predictability but also hold their ways to find excitement from the unpredictability of betting.

This paper discusses the pachinko industry's tremendous market expansion and development in the 1980s through an examination of factors related to the transformation of pachinko parlor management during this period.

The first factor in this development is related to increasing stability of the profit structure of parlors that occurred as sales fluctuations became smaller, a trend spurred by the sudden rise in sales brought about by greater enthusiasm for gambling. At the same time, management became increasingly independent as it no longer needed to readjust the individual pins on game boards, a process that required a great deal of technical skill.

The second factor is related to the supply system of the ‘Fever’ machine, which occurred in response to the pachinko boom. Since there is high fluctuation in demand, machinery manufacturers generally do not have sufficient production facilities to fill orders in a short period of time when popular models appear. However, in response to the sudden popularity of the ‘Fever’ machine, other makers, in addition to the original manufacturer, started to produce and supply imitations, making it possible to meet expanded demand throughout Japan.

On the other hand, competition became more fierce as many new parlors entered the market, enticed by the industry's growth potential. Parlor management, which had previously relied on, among other things, technical expertise related to pachinko board pin adjustment, now found itself confronted with limitations. The industry thus sought new management approaches as it attempted to come to terms with the new situation.