We present a model of parallel search in theorem proving for forward-reasoning strategies, with contraction and distributed search. We extend to parallel search the bounded-search-spaces approach to the measurement of infinite search spaces, capturing both the advantages of parallelization, e.g., the subdivision of work, and its disadvantages, e.g., the cost of communication, in terms of search space. These tools are applied to compare the search space of a distributed-search contraction-based strategy with that of the corresponding sequential strategy.