Before revision:  The Shapley value [ 1 ] is known to be the unique method that satisfies certain desirable properties , and this motivates its use. Unfortunately, despite this uniqueness result, there are a multiplicity of Shapley values used in explaining a model's prediction.
After revision:  The Shapley value [ 1 ] is known to be the unique method that satisfies certain good properties ( a multiplicity of Shapley values used in explaining a model's prediction.