What the angled forefoot was meant to achieve

Why did ships such as Borodino and German battlecruisers use an angled forefoot?

It was an experimental hull-form feature intended to improve stability and speed.

The feature is the sloping transition from the keel into the forward part of the bow. Designers were testing it as one way to improve both stability and speed. Its presence records a period when navies were still exploring how fine hull details affected fast capital ships. Later designers had other methods available to pursue the same performance goals.