A levels are now actually split into two parts - AS and A2.
Everybody studies AS for the first year, if they get good enough grades at AS they move on to A2.
Grades at AS + grades at A2 = A level grade.
Weaker candidates tend not to progress onto A2 level, hence a rise in standards, ie less candidates fail at A2 because they have already dropped out at AS level.
Confused ? you soon will be!
CK