Software architects struggle to choose an adequate architectural style for multi-tenant software systems. Bad choices result in poor performance, low scalability, limited flexibility, and obstruct software evolution. We present a comparison of 12 Multi-Tenant Architecture (MTA) patterns that supports architects in choosing the most suitable architectural pattern, using 17 assessment criteria. Both patterns and criteria were evaluated by domain experts. Five architecture assessment rules of thumb are presented in the paper, aimed at making fast and efficient design decisions. The comparison provides architects with an effective method for selecting the applicable multi-tenant architecture pattern, saving them effort, time, and mitigating the effects of making wrong decisions.