This paper proposes a new metric for mode collapse, which is a scalar value that can be read off from previously proposed measure of mode collapse in PacGAN. Precisely, in the mode collapse region, one can read the two points: (i) where the mode collapse region touches vertical axis ($\delta$-axis) and (ii) where the mode collapse r region touches \delta=1 line. Each one is exactly the same as P_r(support{P_g}) and P_g(support{P_r}) that defend the proposed scalar valued mode collapse measure. This should be explained precisely in the paper, as (i) PacGAN introduced a proper mathematical notion of mode collapse earlier, (ii) the mode collapse region strictly generalizes the proposed metric (iii) mode collapse regions is the foundation of understanding mode collapse theoretically. A new estimator based on nearest neighbor distances are proposed, with extensive numerical validation of the proposed metric.