Pac-Man by the Math: "Inky is Difficult to Predict"
“The blue ghost is nicknamed Inky, and remains inside the ghost house for a short time on the first level, not joining the chase until Pac-Man has managed to consume at least 30 of the dots. His English personality description is bashful, while in Japanese he is referred to as 気紛れ, kimagure, or ‘whimsical.’ Inky is difficult to predict, because he is the only one of the ghosts that uses a factor other than Pac-Man’s position/orientation when determining his target tile.”
— Games is maths!