Peer-review plays a crucial role in the scientific communities; in publishing research papers, in grant applications, and in academic promotion. The whole academic process is centered around peer-review and critical comments from experts in the field. However, there are hundreds of questions about peer-review.
For example, most renowned researchers are interested in acting as peer-reviewers in top journals such as Science, NEJM, etc., and therefore, the quality of peer reviewers could vary a lot.
What is the ideal number of peer-reviewers for an article?
What are the limitations of peer-review?