Comment on 'Systematic survey of high-resolution b-value imaging along Californian faults: inference on asperities' by Tormann et al

[Tormann et al., 2014] propose a distance exponential weighted (DEW) b-value mapping approach as an improvement to previous methods of constant radius and nearest neighborhood. To test the performance of their proposed method the authors introduce a score function. This score function is applied on a semi-synthetic earthquake catalog to make inference on the parameters of the method. In this comment we argue that the proposed methodology cannot be applied to seismic analysis since it requires a priori knowledge of the spatial b-value distribution, which it aims to reveal.