The Raptors and the Grizzlies are "celebrating" their first 15 years in the NBA. Hardly a celebration for both clubs considering one is no longer even in the city they originated in. In fact out of the modern expansion era 2 of the six teams didn't make it to their 15th year, and question is out on the Bobcats.
So this chart documents by winning percentage.
One of the best things about the NBA for professional gamblers is its relatively low deviation compared to other pro sports. It means it's relatively low on the volatility index. The NBA teams were mutual funds, they'd be much more like Yield funds vs equity or sector funds. Not quite cash or bonds, but teams don't tend to vary a lot from one year or another. Each team has their occasional blips, but still fairly low deviation. The bobcats are a perfect example of almost 0 deviation.
Anyways, this isn't a gambling nor investment class. The Raptors were well on their way of being one of the most successful expansion teams until year 7 hit. The 2002-03 season with Lenny Wilkins at the helm was a mess. The back to back drafting of Chris Jefferies and Michael Bradley in 2002 & 2001 really sunk the organization. The Bradley year really hurt as Agent Zero, Gilbert Arenas and Tony Parker were sitting below. The notable pick in 2002 was the 2nd round draft of Carlos Boozer. Hindsight being 50-50 what would this team been like with VC, TP and Boozer? Or even a Zach Randolph.
The team has never really bounced back from that and the Hoffa Years, however the team could have been in much worse shape if it wasn't for the BC acquiring free assets in Anthony Parker, Jorge Garbojossa, having Calderon develop and picking up Nesterovic and TJ Ford.
I think the team is still in recovery mode from Babcock and being the worst of the expansion team years 8-11.
Even though these are expansion teams from the 80s and onwards, I think the last three teams, Raptors, Grizzlies and Bobcats are really in their own era. Both Canadian teams were handcuffed as to how high they could draft.
They've arguably had a better trend in the first half of the franchise's existence compared to the others and was well on it's way to being a contender for the most successful expansion team. In the end, the fact that the Raptors are still in the city, 4th in gate revenue and 9th in attendance is truly what makes this team "successful" and also that it's not in jeopardy of moving (at least anytime soon).