  We present a general formalism for extracting information on the fundamental
parameters associated with neutrino masses and mixings from two or more long
baseline neutrino oscillation experiments. This formalism is then applied to
the current most likely experiments using neutrino beams from the Japan Hadron
Facility (JHF) and Fermilab's NuMI beamline. Different combinations of muon
neutrino or muon anti-neutrino running are considered. To extract the type of
neutrino mass hierarchy we make use of the matter effect. Contrary to naive
expectation, we find that both beams using neutrinos is more suitable for
determining the hierarchy provided that the neutrino energy divided by baseline
($E/L$) for NuMI is smaller than or equal to that of JHF. Whereas to determine
the small mixing angle, $\theta_{13}$, and the CP or T violating phase
$\delta$, one neutrino and the other anti-neutrino is most suitable. We make
extensive use of bi-probability diagrams for both understanding and extracting
the physics involved in such comparisons.
