Tate is a good RB, and good enough to be a starter in the NFL. He does not compare favorably to Foster though. Tate gets the handoff and usually heads for where the hole is supposed to be full speed. He generally cannot cut it all the way back because of how he runs. Foster on the other hand runs with patience. A lot of his big runs start out towards one tackle and then he completely cuts it back outside the other end of the line. He had one today in the first half where Tate could not have made the cut back that Foster did.Another big difference between them is elusiveness and tackle-breaking. Foster led the league last year in broken tackles, was second in RB receptions and led the league in RB receiving yards. He has a good stiff arm. Tate has shown some decent moves making people miss in the scrum, but he hasn't shown the kind of ability in the open field that Foster has. Tate is strong between the tackles. He hits defenders hard and drags them for a couple of yards. He's a bowling ball. But I've also noticed that sometimes he actually seeks out contact with a defender where Foster would have tried to put a move on the guy and gone for another 20 yards. I first noticed it with Tate in preseason and have continued to see it since. Great example was a 4th quarter play against the Colts where Tate got the ball around the edge and only Pat Angerer was anywhere close to him. Tate went right at Angerer, trying to bowl him over rather than make him miss. If he'd made him miss he might have taken it in for a touchdown. Instead he maybe gained an extra yard or two by attacking Angerer.It makes a difference. Foster isn't going to make every guy miss, or break every tackle, but all it takes is one more of those a game to turn a 10 yard run into a 40 yard touchdown. And that elusiveness serves him well in the passing game where he can get the ball in space. At 230 lbs it is tough to arm tackle Foster, and that extra elusiveness he shows over Tate makes it tough to get him wrapped up well.When both are healthy Tate will get touches. He'll be in whenever Foster needs a breather, plus I wouldn't be surprised if he gets a series every now and then. I've really never had much fear that Foster would not be the full time starter though. When watching the qualities that each has as a RB rather than the stat line, it's very clear to me that Foster is the better running back and gives the Texans more flexibility.