Since the 'Betas are shit' thread "dissapeared", I'm posting here this correlation:

Alpha: Vaisiya
Beta: Shudra
Gamma: Kshatriya
Delta: Brahmin

Alternate:

Alpha NT and Beta NF: Vaisiya
Beta ST and Alpha SF: Shudra
Gamma NT and Delta NF: Brahmin
Delta ST and Gamma SF: Kshatriya