  The increasing popularity of metaheuristic algorithms has attracted a great
deal of attention in algorithm analysis and performance evaluations.
No-free-lunch theorems are of both theoretical and practical importance, while
many important studies on convergence analysis of various metaheuristic
algorithms have proven to be fruitful. This paper discusses the recent results
on no-free-lunch theorems and algorithm convergence, as well as their important
implications for algorithm development in practice. Free lunches may exist for
certain types of problem. In addition, we will highlight some open problems for
further research.
