for polish guys, is clay supposed to be his worst surface?
He hit 10 aces in his QF match. Should've won it in two, but couldn't get the break and finally he got broken. In this one, he hit only 3, but still managed to win in straights. Pretty good on clay for a 201 cm guy
As for the clay itself, Nathii probably told you (or you've seen it in our country), that the majority of courts are claycourts, so it shouldn't be not that surprising