What is the courteous lower limit for scores assigned to "Problematic" beers?

In the BJCP scoring system, "Problematic" beers are those that exhibit significant flaws or off-flavors that impact the overall quality and enjoyment of the beer. The courteous lower limit for scores assigned to these problematic beers is set at 13 points. This score acknowledges that while the beer may have substantial issues, it is still not completely devoid of redeeming qualities. A score lower than 13 would typically indicate a beer that is not drinkable or has severe faults, which would not align with the idea of a courteous assessment. Thus, 13 points serves as a threshold that respects the effort put into brewing while also recognizing the presence of serious issues needing improvement.