What is a pachinko machine?
Pachinko
A pachinko machine resembles a vertical pinball machine, but is different from Western pinball in several ways. First, a pachinko machine uses small (11 mm diameter) steel balls, which are rented to the player by the owner (usually a "pachinko parlor," featuring many individual games in rows), while pinball games use a larger, captive ball. The pachinko balls are not only the active object, but are also the bet and the prize. The player loads one or more balls into the machine, then presses and releases a spring-loaded handle, which is attached to a padded hammer inside the machine, thus launching the ball into a metal track. The track guides the ball around the edge of the playing field, then when the ball loses momentum, it falls into the playing field from near the top. Some pachinko machines have a bumper to bounce the ball as it reaches the top, while other machines allow the ball to travel all the way around the field, to fall on the second time that it reaches the top.
Pachinko
Starting in 2007, the majority of Japanese pachinko machines started to include "" (小当たり, small jackpot) into their payout systems. "Koatari" is shorter than the normal jackpot and during payout mode the payout gate opens for a short time only, even if no balls go into it. The timing of the opening of the gates is unpredictable, effectively making it a jackpot where the player receives no payout. "Koatari" jackpots can result in a "kakuhen" as per normal operation, depending on the payout scheme of the machine in question. The main purpose of "koatari" is so that pachinko manufacturers can offer payout schemes that "appear" to be largely favorable to customers, without losing any long-term profit.