Dion Lewis has had a big impact for the Patriots, good and bad

FOXBOROUGH, Mass. -- The New England Patriots lead the Houston Texans 17-13 at halftime, and one of the big storylines has been the impact of running back Dion Lewis -- good and bad.

Let's start with the good.

Lewis has played 14 offensive snaps, leading all Patriots running backs as he's been the primary option over LeGarrette Blount (eight snaps) and James White (three). His 13-yard touchdown catch in the left flat to give the Patriots a 7-0 first-quarter lead, in which he easily beat linebacker Benardrick McKinney, was a good example of the mismatch he creates at times. His quickness is hard to handle in space.

Then Lewis showed his breakaway speed with a 98-yard kickoff return late in the first quarter, which was the Patriots' first kickoff return for a touchdown in playoff history and also the team's first since the 2012 regular season.

It couldn't have been a more impressive first quarter for Lewis, but as good as it was, his second was a disappointment. His lost fumble on a kickoff return set up the Texans' lone touchdown and has kept them in the game.

Those are the types of mistakes that can produce playoff upsets, as the Patriots learned in a shocking 2010 divisional-round loss to the New York Jets.

Since 2000, Bill Belichick's first year as Patriots coach, the team is 137-13 in the regular season when winning the turnover differential. Over that same time span, the Patriots are 34-41 when losing the turnover differential.

One thing to watch for in the second half is whether the Patriots continue to stick with Lewis as the primary ball carrier, or if Blount -- their leading rusher during the regular season -- takes on more of the workload. Blount missed practices Wednesday and Thursday because of an illness.