In this work we probe the possibility of high-temperature conventional superconductivity in the boron-carbon system, using ab-initio screening. A database of 320 metastable structures with fixed composition (50$%$/50$%$) is generated with the Minima-Hopping method, and characterized with electronic and vibrational descriptors. Full electron-phonon calculations on sixteen representative structures allow to identify general trends in $T_{textrm{c}}$ across and within the four families in the energy landscape, and to construct an approximate $T_{textrm{c}}$ predictor, based on transparently interpretable and easily computable electronic and vibrational descriptors. Based on these, we estimate that around 10$%$ of all metallic structures should exhibit $T_{textrm{c}}$s above 30 $K$. This work is a first step towards ab-initio design of new high-$T_{textrm{c}}$ superconductors.