"A long standing prediction (Milgrom 1983) of MOND is that rotating galaxy curves will fall on a single mass-velocity relation with slope 4: Mb \propto Vf4. This prediction is realized in multiple independent data sets. Gas rich galaxies fall where predicted by MOND with no free parameters. There are not many predictions in extragalactic astronomy that fare so well a quarter century after their publication. … a physical understanding for why galaxy formation in the context of ΛCDM should pick out the particular phenomenology predicted a priori by MOND remains wanting."