I didn't say anything about 'improving', or Allen for that matter. I said Jackson will not be able to CONTINUE to do what he did last year because it's so statistically unlikely.
He threw a TD almost 1 out of every 10 throws. For a QB who started 15 games w/a middling YPA and 66%comp that's just totally ridiculous. It's WAY more likely he improves as a passer and his statistics go down a bit than it is he continues to put up the same astronomical stats.