  Four next-to-tribimaximal (NTBM) mixing patterns are widely considered as the
feasible candidates for the observed leptonic mixing structure. With the recent
measurements from T2K, as well as intensive global fits, the interval of
$\sin\delta_{ CP} > 0$ for the Dirac CP-violating phase is persistently small
in the normal ordering while $\sin\delta_{ CP} < 0$ is successively obtained up
to $3\sigma$ level in the inverted ordering. In this paper, we advocate the
fitting results of Dirac CP-violating phase as a constraint, and show that, it
can basically rule out half of the regions allowed by the constraint from three
mixing angles only. In addition, given the small $\sin\delta_{ CP} > 0$
interval, we find that a unique NTBM pattern can be selected out of the four
candidates within $3\sigma$ uncertainty of the latest NuFIT 5.1, when the
patterns are exposed to a Yukawa texture-independent leptogenesis for the
baryon asymmetry of the Universe. For the surviving pattern, we find an
interesting correlation between the Dirac CP-violating phase and the octant of
atmospheric angle $\theta_{23}$ , where $\theta_{23}>45^\circ$ can be predicted
once $5\pi/6 < \delta_{CP} <\pi$ in the normal ordering can be confirmed in the
future measurements.
