Andy's break point conversion looks poor, but this lad is a big server, aces and double faults all over the place. If he manages to come up with the ace or unreturnable at the right moment, there is not much Andy can do except keep plugging away.
Andy is showing what he needs to become a top 10 Player. i know it is reasonably poor psotiion but look at his first serve stats, 81% first serves in which is usually a downfall. What does not usually let him down is his returning ability which is as always as good as the best and it is shown here with 56% recieveing points won.