DALLAS -- Chandler Parsons did not arrive in Dallas with a reputation for being a good defender. He expects that to change.

“We’ve got a great staff that really emphasizes defense,” Parsons said. “Where I'm coming from, offense was always our main goal. Now we’ve got to win games and championships on the defensive side. I'm totally locked in and dialed in to do that.”

In comparison to former teammate James Harden, Parsons was a lockdown defender with the Houston Rockets. However, in comparison to the rest of the league, Parsons was pretty mediocre on that end of the floor.

According to Synergy Sports, Parsons ranked 190th as an overall defender last season, allowing 0.88 points per possession. He ranked 219th in isolation (0.93) and 204th in post-up situations (0.94). Parsons was well above average guarding pick-and-roll ballhandlers, ranking 70th and allowing 0.74 points per possession.

With the Dallas Mavericks, Parsons has large shoes to fill on defense. Many shoes, for that matter. Shawn Marion, aka “The Matrix,” was the Mavs’ best defender for the last five seasons and guarded everyone from point guards to power forwards.

The Mavs hope to use the 6-foot-9 Parsons in a similar fashion, which would give coach Rick Carlisle tremendous flexibility to experiment with different lineups.

The Mavs’ emphasis on defense isn’t just about their system or demanding effort. They have stressed it all summer with Parsons. He has worked extensively with Jeremy Holsopple, the team’s new-age strength and conditioning coach whose official title is athletic performance director, to improve his strength and quickness with an emphasis on defensive functionality.

“Whereas most teams don’t even work on the defensive stuff,” Mavs owner Mark Cuban said. “At least with Chandler, he has never been through that before. So just physically training them to be able to move in a way that supports a defensive effort is something he hasn’t gone through yet.

“So I think that’s one big step forward for him.”

Parsons has worked to become quicker and stronger. The Mavs’ coaching staff can help make him smarter. It’d be a major disappointment if he isn’t a drastically improved defender.