I accept the challenge.In my opinion,"the blind man seeing" is the what we call perception or imagination whereas belief is totally different thing and is related to the values and obtained from the experience of the people.
Firstly,I wanted to say that in a debate one should show the audacity to express oneself clearly so that the opposing contender can debate on it.You should have the courage to listen and accept the other party's opinion rather than just trying to trap the opposite side.
Also,if you try to trap the opposite side you should have some grounds for that because you mentioned "knowledge is memory, opposite of belief".Adding to it,belief is not unknown.It is something that may or may not be realistic but known.
Firstly,belief is a personal thing and it differs from person to person.Here,you say I don't know means the other person don't know how many fingers you had kept at back.But,your belief cannot be defined what the other know.Your beliefs are defined by whether you know how many fingers are at back and that is absolutely yes.
So,one's beliefs are definitely known to oneself.The only thing is that it may or may not be true or realistic.So,it cannot be said as blind man seeing.
Secondly,the justification you required about whether knowledge and belief is now clear.Even then let me explain clearly,knowledge is what we know,I completely agree with that but belief is what we don't know is completely unacceptable as discussed above.
Now the justification you needed in the third round that how knowledge is not opposite of the belief lies in your argument only that belief are useful when you don't know.That doesn't mean that belief is what we don't know.So,now I think it is clear that the two cannot be mentioned as opposite.
It is definitely position based but here we have talked until now what belief is.So,here you selected the "I don't know" side is not the position based selection but it is an wrong understanding of yours because as I had mentioned earlier it is known and differs from person to person(personal).Thus,its not opposite of knowledge as you mentioned.
So,I completely disagree with the "belief is a blind man seeing".