What is the Minecraft skin detection algorithm?

Question

Java

I did not find such a question and information on it, so I ask - what is the algorithm for determining the skin of a minecraft character by nickname? Depending on the nickname, Steve or Alex is chosen and this is a pattern, I can’t determine it myself, and I’m asking you.
PS I know that the site is not suitable, but maybe someone knows.

Answer 1

From the game source:
DefaultSkinHelper:

public static Identifier getTexture(UUID uuid) {
      return shouldUseSlimModel(uuid) ? ALEX_SKIN : STEVE_SKIN;
   }

   public static String getModel(UUID uuid) {
      return shouldUseSlimModel(uuid) ? "slim" : "default";
   }

   private static boolean shouldUseSlimModel(UUID uuid) {
      return (uuid.hashCode() & 1) == 1;
   }