There are few things I superficially know, which I do not know how to make a coherent statement through them.
By pair-of-pants decomposition, we know that the four-punctured sphere can be obtained by gluing two three-punctured sphere. Similarly, one punctured torus is obtained by self-gluing a three-punctured sphere, and two punctured torus is obtained by gluing two three-punctured sphere two times.
The torus is a double cover of a 2-sphere with four ramification points.
The Riemann-Hurwitz formula gives the relationship between the Euler characteristics of two un-punctured Riemann surfaces $S,S'$ where $S'$ is a ramification covering of order $n$ of the $S$. $$\chi(S')=n\chi(S)$$.
My question is: Is two-punctured torus a double cover of four-punctured sphere??