The silicon lottery binning figures for i7 8700k's:
As of 11/11/17, 100% of tested 8700Ks were able to hit 4.9GHz or greater. ( 1.387V Vcore -2 AVX Offset)
As of 11/11/17, the top 81% of tested 8700Ks were able to hit 5.0GHz or greater. (1.40V Vcore , -2 AVX Offset)
As of 11/11/17, the top 58% of tested 8700Ks were able to hit 5.1GHz or greater. (1.412V Vcore , -2 AVX Offset)
As of 11/11/17, the top 30% of tested 8700Ks were able to hit 5.2GHz or greater. (1.425V Vcore , -2 AVX Offset)
As of 11/11/17, the top 6% of tested 8700Ks were able to hit 5.3GHz or greater.( 1.437V Vcore , -2 AVX Offset)
That's from 100+ CPUs