It's one point from a win and minus one point from a lose. That is the same
as getting zero from a lose and one from a draw and two from a win, that is
the same as getting zero from a draw, half a point from a draw and one point
from a win. They used to count only wins at older WC matches so that the
winning score couldn't be reached by making draws; they gave up of that when
Kasparov's WC match vs. Korchnoi lasted 48 games and it was still not at six
wins (Korchnoi had five points and Lasker had just won two games in a row to
make it 5-3).