Boston fans can be forgiven if they struggle to recall the Celtics career of D.J. White. The journeyman power forward, currently plying his trade in the Italian Alps, logged less than 100 minutes in green at the tail end of the 2012-13 season. However his impact or, more directly, the impact of his inclusion in a trade, is still being felt by the franchise today.

The Celtics front office, led by Assistant GM Mike Zarren in these matters, is among the best in the league at manipulating the NBA’s collective bargaining agreement. Full of arcane rules and loopholes, the CBA is fertile ground for a franchise looking to gain an edge over their competitors. For example, the trade rules that most fans have become somewhat familiar with through ESPN’s Trade Machine go quite a bit deeper than simple salary matching and have been an area that the C’s have worked to their advantage.

It’s now well known that Danny Ainge & Co. turned a trade exception into Isaiah Thomas and Tyler Zeller. What’s less well understood is how a simple open roster spot made everything possible. Enter D.J. White…

In March of 2013, after the trade deadline had passed and all the “major” moves completed, the Celtics found themselves with an open roster spot and a minor need for a backup bruiser. During the “New Big 3” era the team regularly kept a spot open so they could react quickly to a trade or potential veteran signing. In 2013, with the title window closing, they instead used that spot to sign White to a pair of 10-day contracts. At the end of the second deal, D.J. was signed for the remainder of the season. As is almost always the case with these types of deals, a second non-guaranteed year, for the minimum contract, was added. This is done in part to give the team “upside” if the player performs well but also because it gives the team a small trade chip. It ended up not mattering but last year Chris Babb (Phil Pressey could have played the role) was signed for the same purpose.

In the summer of 2013 Ainge made his move and shipped Paul Pierce and Kevin Garnett to Brooklyn. The initial trade reports had the Celtics sending Truth, KG, and Jason Terry but did not mention White. This could simply have been an oversight, the exact details of trades aren’t always reported right away, but those three would have made a valid trade with everything the Nets sent in return. If anything, it seemed that the Celtics were sending too much money. So why did D.J. White end up in the deal?

The CBA affords a team some flexibility in how they report a trade. In sending Pierce, Garnett, and Terry, the Celtics would have been able to create a trade exception for $7,375,537, the difference between the contract of Kevin Garnett and the sign-and-trade deal of Keith Bogans. However, the team worked out that by adding a small salary they could reconfigure the trade to instead make a $10,273,136 TPE, the difference between the contracts of Pierce and Bogans. D.J. White, signed in part to play this exact role as salary fodder in an unknown future trade, fit the bill. His minimum salary contract could be absorbed by the Nets with no salary matching implications and then waived, so they didn’t care either way.

Nearly a year later, the C’s still sat on that $10M+ TPE when then Cavs went shopping for cap space to facilitate their signing of LeBron James. Had the Celtics not included White in the Nets trade and built only a $7.3M TPE, the trade that brought Zeller and Marcus Thornton could not have been completed. It’s possible the deal could have been broken into smaller parts, but at best Boston would have ended up with just Jarrett Jack and a lesser pick.

The pick they did receive, along with Marcus Thornton’s expiring contract (Jack had a longer deal), was all it took to free All Star Isaiah Thomas from his desert purgatory in Phoenix.

That’s how a smart front office plays all the angles. An open roster spot becomes a non-guaranteed deal. The non-guaranteed contract is added, counterintuitively, to a major trade to scrape together a larger trade exception. The trade exception is inserted, two days before it expires, into a three team trade to take the contracts of a backup center and an overpaid guard for the ransom of a first round pick. The pick is flipped for an underused PG. An open roster spot and a little money becomes an All Star in less than two years. Remember D.J. White; he played his part.