# How is there a $\frac{1}{poly(n)}$ bias in a multiple-round coin tossing protocol with commitment?

On p.2, Example 1.1 (in this paper), there is a description of a coin tossing protocol with bias 1/4. In the paragraph below the example, they note that for a protocol with $$r$$ rounds (assume for the sake of clarity it is $$poly(n)$$) there's a bias of $$\frac{1}{r}=\frac{1}{poly(n)}$$.

I am quite new to Cryptography, and since the paper they cite in this context is quite old and very different to their example, I'm left with two questions:

1. How can their example (Example 1.1) be adapted to a $$poly(n)$$ round coin-toss protocol with bias at most $$\frac{1}{poly(n)}$$?

2. How is the final outcome in a multi-round coin toss determined? (i.e., we tossed more than one coin each, so what is the final result?)