  Recently a number of randomized 3/4-approximation algorithms for MAX SAT have
been proposed that all work in the same way: given a fixed ordering of the
variables, the algorithm makes a random assignment to each variable in
sequence, in which the probability of assigning each variable true or false
depends on the current set of satisfied (or unsatisfied) clauses. To our
knowledge, the first such algorithm was proposed by Poloczek and Schnitger; Van
Zuylen subsequently gave an algorithm that set the probabilities differently
and had a simpler analysis. She also set up a framework for deriving such
algorithms. Buchbinder, Feldman, Naor, and Schwartz, as a special case of their
work on maximizing submodular functions, also give a randomized
3/4-approximation algorithm for MAX SAT with the same structure as these
previous algorithms. In this note we give a gloss on the Buchbinder et al.
algorithm that makes it even simpler, and show that in fact it is equivalent to
the previous algorithm of Van Zuylen. We also show how it extends to a
deterministic LP rounding algorithm; such an algorithm was also given by Van
Zuylen.
