Firstly, eye test. Are we able to dominate the line of scrimmage and push the D back consistently on run plays. If we are doing this along with pulling and trapping we are already better than last year. We have to get our YPC up. I would like to see us in the top 6 in the league in several rushing statistics (ypc, per game) we were 9th last year so it is going to take a noticeable difference to improve to that level. All of this coincides with scoring points and winning games. Obviously that can't be the only metric because there are other factors that play into those outcomes, but I think if we can improve our rushing attack to top 6 in the league it will go a long way in making those outcomes favorable for us.
I think it is a given our passing game will get better and that's less on the o line so I'm not as concerned with the passing stats as it relates to line improvement.