James Harden slides sideways or steps backward, and the screaming starts.

Whether seated on the opposing bench or on a stool in a sports bar, somebody is insisting that Harden must have traveled between the time he finished dribbling and launched his shot from a different spot. Traveling will be an emphasis this season for officials, who are determined not to allow offensive players to gain an extra edge by taking an extra step.

Scoring stars like Harden already got an advantage once hand-checking on the perimeter was no longer legal, so they can't be given another one.

"If we can't allow people to hand check, we can't allow them to travel because then they're almost unguardable," vice president of referee operations Mark Wunderlich said.

That said, most times when Harden does his signature step-back, he doesn't travel.

"It is legal, except for the fact that he gets a third step in every now and then when his rhythm is just off, which shows you the highlight of how difficult it is," said Monty McCutchen, the NBA's head of referee development and training.

That's why referees are working harder to get it right.

Critics of the NBA — and even some fans — have long sneered that the league doesn't call traveling. McCutchen said data showed officials were missing about two per game, but the way the game is played today can make those misses more penal for the defense.

Players are bigger, faster and more skilled, and even big men who would have been centers in a previous generation are now do-everything forwards like 6-foot-11 MVP Giannis Antetokounmpo. He already gets far enough with the two steps that are legal, forget when allowed a third.

McCutchen compared the difference with Tiny Archibald, a 6-1 guard who played in the 1970s and '80s.

"He covered 10 feet with his two steps," McCutchen said. "How far is Giannis covering? The game has changed."

So officials have begun to change with it, altering the way they were taught to officiate when McCutchen and Wunderlich were on the floor. Before, referees were trained to look first at the defensive player. Now they have reversed their sequencing, looking first at the offensive player's feet to make certain a legal pivot foot has been established and not changed.

And the league added new language in the rule book to define the "gather," to clarify how many steps a player can take after receiving the ball or completing his dribble.

At the referees' preseason meetings and training camp last week, McCutchen said officials studied replays of three travels each time they returned from a break, and had a dedicated 45-minute session on traveling.

An educational video was sent to teams, and the referees visited the coaches' preseason meetings, where they had a traveling station with two players on the floor so they could do demonstrations for the coaches.

And Houston coach Mike D'Antoni said the league stressed that Harden's step-back jumper is legal.

"They made a point, which is great, to tell every head coach that is not traveling. It's not traveling," D'Antoni said. "So hopefully coaches will quit complaining and hopefully you guys in the news will understand that that's not traveling. There's other points that we have to clean up that are traveling and the NBA is going to try to do a better job of that."

San Antonio coach Gregg Popovich quipped last year that the step-back 3 came when players "jump backwards and travel and shoot a 3." But the leaders of the referee team praised Harden for his cleverness and creativity.

"On the dribble, we always talk about dribbling you can take two legal steps to the basket, right? No one ever thought about on the gather after you dribble you can take two legal steps backwards," Wunderlich said.

Added Jason Phillips, who will oversee the Replay Center: "The rulebook doesn't state that the two steps have to be in any direction."

Harden said it never should have been a debate, because if he was traveling then referees would have been whistling him for it.

"I'm tired of hearing that's a travel, from coaches, from other players, from haters, fans, whatever you want to call it," Harden said.

But he acknowledges it looks awkward, so the referees know they have to educate teams and fans just as much as themselves. There is no new rule or even a new interpretation of traveling, just a desire to correctly call the travels that are in the books.

That's why it's the biggest emphasis on the preseason list of points of education.

"The first one is traveling and the second one is traveling and the third, fourth and fifth one are traveling," McCutchen said. "I'm only joking to show that there are POEs and then there are POEs. We really want to get better at our fundamentals of the game and traveling is a big part of that."