I discuss recent progress in lattice calculations of $B to D^{(*)} ell u$ form factors, important for the precision determination of $|V_{cb}|$ in the Standard Model (SM), and for testing SM expectations of lepton flavor universality in observables $R(D^{(*)})$. I also discuss progress in calculations of the related $b to c$ semileptonic decays $B_s to D_s^{(*)} ell u$ and $B_c to J/psi , ell u$ now experimentally accessible at the LHC.