The reason why he doesn't get behind the defense is because he never receives a good pass. He's had some decent runs, but the pass is not arriving. The attackers are dependent on a midfield with creativity that can feed them. Without Barton all our creativity is gone. I don't have the statistics in my head, but I think we've not won one single match when Barton is out. It's not just Loven who's not functioning, the whole team suffers.
Barton's played all but about 6 games this season, man. Guthrie was there playing some lovely passes when he got time on the ball last season.
His runs are usually in straight lines - easy to track, a second too early or a second too late.