Do You Understand the N.B.A. Salary Cap? Imagine Enforcing It.

The team wanted to sign Paul as a free agent, but didn’t have the cap space. One option to get it was waiving the sharpshooting big man Ryan Anderson and spreading the impact of his contract over several years, called stretching or using the stretch provision.

But the Rockets wanted to keep Anderson. So the front office, primarily Stone and Eli Witus, an assistant general manager, found a loophole in the collective bargaining agreement. The Rockets could stretch Anderson immediately, sign Paul when free agency began and then re-sign Anderson. A new rule barred the move, but it wasn’t set to take effect for at least a couple days.

Stone said the league argued that the team’s plan violated the collective bargaining agreement in spirit. (A league spokesman said that even without the new rule, the N.B.A.’s position was that the maneuver would have violated other regulations .)

Ultimately, Houston traded for Paul instead of signing him as a free agent, and kept Anderson.

Mark Cuban, who owns the Dallas Mavericks, said in an email that his disagreements with the cap group have been mostly limited to defining “likely” bonuses — payments to players based on thresholds that have a high probability of occurring. Likely bonuses count against the cap immediately, affecting how much teams can spend elsewhere.

If a player disagrees with how the cap group interprets the collective bargaining agreement, there is an arbitration process.

“We’ve had a fair amount of fights,” said Ron Klempner, the senior counsel for the players union, who also said the relationship between the two factions was cordial.

One dispute came during the 2011-12 season, when several prospective free agents, including Jeremy Lin and Chauncey Billups, were claimed off waivers. Under the collective bargaining agreement, teams can go over the salary cap to re-sign and give raises to their own players if the player has been on the team for three years, a cap exception known as “Bird Rights,” named after Larry Bird. If a player gets traded, he keeps those rights. The union argued the exception extended to players claimed off waivers. The league disagreed. The union won in arbitration.