  Black hole horizon is usually defined as the limit for existence of timelike
worldline or when a spatially bound surface turns oneway (it is crossable only
in one direction). It would be insightful and physically appealing to find its
characterization involving an energy consideration. By employing the Brown-York
[1] quasilocal energy we propose a new and novel characterization of the
horizon of static black hole. It is the surface at which the Brown-York energy
equipartitions itself between the matter and potential energy. It is also
equivalent to equipartitioning of the binding energy and the gravitational
charge enclosed by the horizon.
