Gay had been struggling mightily and wasn't exactly carrying his teammates towards a playoff berth, but moving him for role players and financial flexibility was a clear signal that the front office was ready to move beyond this roster iteration and start designing a newer, better version.
But a funny thing happened on the way to the lottery. Dumping Gay turned out to be a much bigger, immediate positive than anticipated, and the Raptors catapulted themselves to the top of the relatively weak Atlantic Division.
Since the trade the Raptors are 10-5 and have been outscoring opponents by an average of 5.0 points per 100 possessions. That mark would be the ninth best in the league if posted across the entire season.
Gay's struggles over the past two seasons had pretty much destroyed any remaining perception of him as a top dog to build a team around. It seemed pretty clear that moving him might offer some short-term improvement, but it's hard to imagine anyone in the organization expecting a turnaround like this.
The Raptors' improvement since the trade has come on both sides of the ball and unfortunately for Gay, a lot of it can be traced to his absence.
The following two radar graphs show how the Raptors have been allocating their offensive possessions this season, and at what rates of efficiency. The light purple line represents what percentage of their overall offensive possessions were used on each possession type. The dark purple line represents their efficiency by points per possession. All the data here comes from mySynergySports (subscription required).
This first graph shows their offense before the trade.
Ideally, a team would use most of its possessions on the most efficient possession types, but there are limits to how far this can go. Many of the most efficient possession types—things like offensive rebounds, transition and cuts—require openings in the defense that simply can't be created on every possession.
Most teams settle into a balance between pick-and-rolls, isolations, post-ups and spot-up jumpers as the engines for their offense. Of those, possessions that are used in the pick-and-roll or on spot-up jumpers are generally more efficient options.
We can see from the graph that early in the season the Raptors offensive distribution was heavily tilted towards options that required a single player attacking the defense. Before the trade isolations, post-ups and possessions finished by the ball-handler in the pick-and-roll accounted for 39.8 percent of their offense.
This second graph shows their offensive distribution since the trade. I've highlighted the two really significant changes.
Since the trade the Raptors are using far fewer offensive possessions on isolation plays and post-ups, the offensive "specialty" of Gay. The difference has been a lot more offense coming out of the pick-and-roll, especially by the screeners and a lot more spot-up jumpers.
The really interesting thing is that despite improving by 3.5 points per possession overall since the trade, the Raptors' offense hasn't gotten significantly more efficient on any specific possession type. They've just been allocating their possessions more efficiently.
Raptors head coach Dwane Casey admitted as much to Zach Lowe of Grantland.com last week:
All the same sets. The ball is moving. Guys are playing together. Everyone is buying in. No disrespect to Rudy, but he's a different type of player.
When we turn to the video we can quickly see how removing Gay has freed things up for the Raptors to get more out of their pick-and-roll attack.
As the Raptors bring the ball up the floor, Amir Johnson is headed for the right block, only to find that Gay has already set up there. He then runs out to set a high screen for Kyle Lowry, but with Gay calling for the ball on the block there's really nowhere to run the pick-and-roll. Realizing their limited options, Lowry throws the ball into Gay and both he and Johnson clear out for Gay to go to work.
Setting aside the fact that Gay doesn't seem to be on the same page as his teammates as far as what an ideal offensive possession looks like, the spacing of this play essentially dooms it from the start. With both bigs stationed under the basket there is almost no option here for Gay except a fall-away jump shot.
This situation was often the norm for the Raptors' offense. Potentially potent pick-and-roll actions were often stymied by ball-stopping isolation attacks or poor spacing by Gay.
Compare that possession to the well-spaced pick-and-rolls the Raptors' have been able to run without Gay on the floor. Here, the same high pick-and-roll with Johnson and Lowry has plenty of space to fill the center of the floor with both wings spaced out behind the three-point line.
That sort of spacing has also worked to create wide open three-point looks.
Here the Spurs' defense collapses on the screener, Patrick Patterson, leaving both wings all alone.
Here, a side pick-and-roll with Lowry collapses the defense, and excellent ball movement on the weak side creates an open corner three-pointer for Ross.
These kinds of shots just weren't consistently available when Gay was holding the ball on the wing, attacking his man one-on-one.
Although Gay's inefficient shooting was hurting the Raptors' offense, the types of shots he was taking appears to have been equally as damaging. His possessions haven't been redistributed to a single player of drastically improved quality. But taking him off the floor has allowed them to run their sets more smoothly and with better outcomes.
The Raptors are getting a better product because they've been able to execute the same process more cleanly.
As Rob Mahoney of Sports Illustrated noted, the Raptors' improvement hasn't just been on the offensive side:
Toronto’s offensive uplift, though, has thus far been surpassed by the team’s defensive gains. Since completing the Gay trade, the Raps have locked down defensively, holding opponents to 4.4 fewer points per 100 possessions. Their new marks mimic that of a top-five defensive outfit, a stark improvement over the mediocrity in coverage that had become their standard.
Like on offense, a lot of the improvement has been addition by subtraction. Gay's departure has moved Terrence Ross into the starting lineup at small forward. With Ross, Lowry, Johnson, DeMar DeRozan and Jonas Valanciunas on the floor the Raptors are allowing an average of 101.1 points per possessions. That number is nowhere near elite, but it's a huge improvement from the 107.8 that group was giving up with Gay swapped in for Ross.
Ross is a much more active defender than Gay—or DeRozan—and he gives the Raptors a different sort of intensity on the wings. So far this season he's forced opposing pick-and-roll ball-handlers into turnovers on an astonishing 29.3 percent of their possessions.
Here, playing off the ball, he sags down on the pick-and-roll ball-handler but still gets back to close down the passing lane for a kick out.
This kind of active perimeter defense just wasn't the norm with Gay and DeRozan on the wings together. It put a tremendous amount of pressure on the interior defenders to corral penetration and stressed their entire defense.
Ross is not a game-changing individual defender, at least not at this point in his career. But he does add just enough aggression and activity to make everyone else's defensive jobs a little bit easier.
Addition by subtraction is a common-enough concept in professional sports and it could be seen coming a mile away with the Rudy Gay and the Raptors. But in the Raptors' case it hasn't taken the forms we're most accustomed to.
His departure hasn't been just about removing negative outcomes. It hasn't been about creating a vacuum for some other player to step forward, taking a drastic leap in production. What sending Rudy Gay to Sacramento accomplished, more than anything else, was removing a considerable amount of friction and resistance from their offensive and defensive systems.
All the parts are working better, smoother, more cohesively. What looked like a fundamental rebuild has now become a much more complicated question.