Which ranking does always beat beginners?

[illluck]

Yes, and there is of course the danger of you losing stones by playing so many games against a weaker player. However, for the purpose of the question I assumed you can ignore these two factors as it's only the probability of losing a single game (at least no more than 200 :p).

[snorri]

Exactly! I think having that ranking is a definition of being good at go. That's my motivation.

A fear of losing is unfortunately one of the few things that can prevent a player from progressing past the stage of being a beginner. I'd recommend reading David Mechner's advice. I particular, this part, which is one my favorite pieces of advice ever:

Inevitably, you won't feel comfortable with a concept when it's first explained to you. The point is, if you don't go through step 2, you'll never get to step 3. The whole point here is that you have to do what you think is right intellectually before it feels right, and just by going through the motions, it will come to feel right and you'll improve. Some people find this hard to do because playing something you don't really understand feels dangerous, and danger in go means you might lose. But if your goal is to improve, don't worry about winning or losing. Really. Look; now I'm a 6-dan. Who cares how many games I lost when I was 5-kyu?

[tapir]

Also, if your answer to the question is "it depends", try to come up with a rank which would be absolutely impossible to beat.

If you are winning more than half of your games you are not giving the correct handicap!