I know we don't do a lot of NBA chat around here, but thought some may find this interesting. The USATODAY followed NBA Officials for a week and is providing a multi-part story. Link to Part 1 is below. An interesting excerpt on "traveling" from the article is below.
A ref's life: To get ready, officials often go to the tape - USATODAY.com
Many fans believe NBA referees ignore all but the most blatant of traveling calls. But after countless hours of video review, Foster maintains that most of the time, they get it right.
The NBA allows a "two-count rhythm" after a player gathers the ball. But fans don't recognize that a player must have complete possession of the ball, and that the steps start after the gather. "In some cases that can be two very large strides to the basket," Foster says. "
After reviewing tape it is often seen that what fans might have thought was a travel is in fact just an 'awkward' legal move."
At other levels of basketball, players are whistled for traveling if they fall to the floor with the ball. Not so in the NBA — as long as the player gains no advantage by rolling or sliding away from an opponent.
An NBA player is also free to rise if he gains control of the ball while on the floor.
There is an instance where NBA referees call traveling that won't be called at other levels. It's the "hop-hop" travel, when a player alights off a foot and lands on the same foot, i.e., a "jump stop."