The video in question is an example of a legal gather -- Giannis takes two steps then finishes after picking up the ball. Giannis
also travels in that clip while dribbling up the court when he takes multiple steps between dribbles. Even in the Luka Doncic video above that, his step back move
is legal since it only uses two steps but his hesitation stutter step at mid court is a travel because he shuffles his feet to change direction while the ball is in the air then continues dribbling. If you watched basketball in the 90s, these are all obvious traveling violations.
Here's the actual rule as written:
Section II—Dribble
- A player shall not run with the ball without dribbling it.
- A player in control of a dribble who steps on or outside a boundary line, even though not touching the ball while on or outside that boundary line, shall not be allowed to return inbounds and continue his dribble. He may not even be the first player to touch the ball after he has re-established a position inbounds.
- A player may not dribble a second time after he has voluntarily ended his first dribble.
- A player who is dribbling may not put any part of his hand under the ball and (1) carry it from one point to another or (2) bring it to a pause and then continue to dribble again.
- A player may dribble a second time if he lost control of the ball because of:
- A field goal attempt at his basket, provided the ball touches the backboard or basket ring
- An opponent touching the ball
- A pass or fumble which touches his backboard, basket ring or is touched by another player.
- PENALTY: Loss of ball. Ball is awarded to the opposing team on the sideline nearest the spot of the violation but no nearer the baseline than the foul line extended.
The two lines I highlighted are the rules being violated but there's some room for interpretation in both because the language is not precise...
Giannis running up the court while only occasionally dribbling the ball could be (and I would argue
should be) interpreted as running without dribbling.
Luka and Tyrese using a hesitation dribble to throw in two or three quick change of direction steps before continuing their dribble should count as a discontinued dribble. And in the Tyrese clip he goes straight from a three step hesitation move into a two step gather which is all kinds of illegal and yet somehow, by the sheer fact that neither the commentators, officials, or official NBA TV twitter ever acknowledge it... also not illegal?