Obviously a winning record helps.
Anything is is up in the air. I think it's more how we play, how close are games, is Tru in there improving? Are we on an upward swing towards the end? Do we play well and beat some of our divisional foes? Ultimately, does he still have the respect of the team? So much would factor in.
All that said, and I think Pace wants to bring in "his" guy. From what I've read, Fox was sort of thrust upon him. If Fox is doing well, Pace will leave it alone, if not, I'm sure he will want to make a change...
Another losing season and it gives him all the ammunition he needs. To the best of my recollection, no Bears coach in the history of the team has survived three losing season in a row...
And in the end, I think fox needs to no no less than 7-9 with an upward swing at the end or he's gone. Or we go something like 0-10, Tru comes in and we end up 6-10, or 5-11. Something like that - that shows a significant upwards trend.