In general, an efficient bracket maximizes final protein yield by minimizing the path length (i.e., number of sequential reactions) of any given segment. The simplest way of choosing between two brackets, therefore, is to choose the one with shorter yield-limiting path length (i.e., smaller Max Path), and if this score is tied, shorter path lengths among all segments on average (i.e., smaller Avg Path). Each path represents a yield loss, and reactions with poor expected yield are equivalent to longer paths. This consideration is reflected in the score as a +1 path penalty for poor-yielding thioesters (generally I, L, K, T, and V 28 ) or a +2 path penalty for sterically hindered thiols (e.g., V [as Pen]). By the same logic, steps that do not reduce yield (i.e., most side-chain modifications performed one-pot with NCL) are not counted in path length.