Fuzzy rule based system: Should rules contain all inputs and outputs? I am trying to design an FRBS using Matlab fuzzy tool box. The fuzzy system will be used to predict player's type based on the inputs and a set of rules defined by experts. 
I have 6 inputs and 4 outputs (types of players). The given rules do not concern all inputs. Specific inputs are used for each player type.

Is it imperative to include all inputs and outputs in a rule? 
Also is there a min/max of rules that an FRBS should include or does it depend on the experts expertise?

Thank you for your help.
Not really. It is possible to create fuzzy logic model without setting whole ruleset. But there is a risk, that model will perform worse in some unexpected situations which would be handled by missing rules.

However, it is possible to figure out fuzzy rules basing on data. I personally used Wang-Mendel method and it worked fine for me: still 6 inputs and 4 outputs will be many of rules to deduce :(. Wang - Mengel method is described in this paper: http://sipi.usc.edu/~mendel/publications/Wang%26Mendel%20SMC%2011-12-92.pdf