Theory of Inclusive B Decays

In this talk I briefly review the current status of the theory of the inclusive $B$ decays: $\bar{B}\to X_c\mathrm{\ell }{\bar{\nu }}_{\mathrm{\ell }}$, $\bar{B}\to X_u\mathrm{\ell }{\bar{\nu }}_{\mathrm{\ell }}$, and $\bar{B}\to X_s\gamma$. I try to answer three questions: what is the current “state of the art”, can the theoretical prediction be improved, and will it lead to a smaller theoretical uncertainty.