Abstract: The axial coupling g_A=1.2723(23) is one of the essential characterizations of the nucleon and plays a fundamental role in our understanding of nuclear physics, controlling nuclear beta decay and pion exchange. It has long been considered a critical benchmark for lattice QCD and yet has proved substantially more challenging to compute than expected. I will describe our recent calculation, g_A = 1.283(17) and explain computational strategies that, when combined with improved algorithms and leadership-class computing, have unlocked this and other nuclear matrix elements.