Another reason for incorporating "koataris" is that they make it possible for a machine to go into "kakuhen" mode without the player's knowledge. This is referred to as "" (潜伏 'hidden') "kakuhen" because it does not occur in any of the jackpot modes. A player sitting at a used pachinko machine offering a 1 in "x" chance of hitting a jackpot in normal mode can hit it within "x" spins easily because the previous player did not realize that the machine was in "senpuku". This induces players to keep playing their machines, even though they may still be in normal mode. Japanese pachinko players have not shown significant signs of protest in response to the incorporation of "koatari"; on the contrary, battle-type pachinko machines have become a major part of most parlors.