Why compatibilism is missing from the line
A third position
Compatibilists hold that a person can be responsible even if the past and the laws settle what they do, because responsibility tracks the quality of the will rather than an uncaused power. That view denies an assumption shared by the two poles. Putting it at 50 would pretend that “sometimes determined” is the same idea.
How an answer is kept
Where the questionnaire offers a compatibilist description, choosing it is stored and reported. It does not move the agency index. If you choose it, the result says so in words. The absence of a letter for compatibilism is a limitation of the model, stated on purpose.