Recently, I have been reading up on few blogs about rolling hashes: dacin21's [On the mathematics behind rolling hashes and anti-hash tests] and rng_58's [Hashing and Probability of Collision]. Both of them showcase different hashing technique.

Method described in dacin21's blog:

Note: in the above equation a is the base

Method described in rng_58's blog: H(a) = (r+a_1)(r+a_2)...(r+a_n)

Note: in the above equation r is the base

Are there any differences between the two in terms of use-case and other parameters?