abstract: The study of billiards in rational polygons is intimately connected to moduli spaces of flat surfaces and, in this context, a prominent role is played by the so-called saddle-connections. In this talk, we discuss some results (with a particular attention to the recent works by Athreya-Fairchild-Masur and Bonnafoux) concerning the possibility of effectively counting saddle-connections of typical flat surfaces using Nevo's ergodic theorem and the exponential mixing of the Teichmueller flow.