A-2 catches A-1's throw-in airborne and lands simultaneously on both feet in the frontcourt. A-2 then steps into the backcourt. Is this a legal play according to the official?

In this scenario, the action of A-2 landing simultaneously on both feet in the frontcourt while catching A-1's throw-in signifies that A-2 has established a legal position in the frontcourt. However, the crucial factor in this situation is A-2 stepping into the backcourt after having gained possession.

According to the rules, once a player catches or gains possession of the ball in the frontcourt, they cannot step back into the backcourt without first relinquishing that possession, such as by dribbling. Since A-2 steps into the backcourt immediately after catching the ball without dribbling, it results in a violation—specifically, a backcourt violation. This means that the play is not legal within the context of the game's rules.

The correct answer reflects the understanding that a player's position, where they can legally play the ball, is critical to determining the legality of their actions following a throw-in.