While I'm not going to say the lottery process is or isn't fixed, I will say that the process needs to be changed. I understand why it was implemented, but it's hurting several franchises more than it's helping to thwart those that may choose to lose on purpose in order to improve draft position. Any franchise that would purposely lose to secure a top pick certainly will do the same to acquire more ping pong balls and the chance to jump other teams.
If they really want to prevent a franchise from tanking at the end of a season, as Houston may or may not have done in back-to-back years to get Sampson and Olajuwon, all they need to do is slot teams based upon a 3 year average. For example, you'd take this past season's record and combine it with the previous two. You then slot the non-playoff teams in reverse order of their combined winning percentage.
Problem solved.
Doing it this way prevents a team from tanking the last 2 months of a season and being rewarded with #1 based off that one season. Sure, a team on the fringe could still opt to do so if they know a 3-yr average between themselves and another team is going to be close. However, you get that anyway with the current ping pong process. So what's the difference?
The difference between the current process and what I'm proposing is teams that have been bad for a string of 3 years aren't going to be consistently penalized and see their draft position fall nearly every single year. The Kings, for example, have been in the lottery 16 times. Of the 16, they have lost position in the lottery 13 times. THIRTEEN! Including today, they have maintained position only 3x and improved position only ONCE. That's a flawed system. And the Kings aren't the only one's finding themselves buried in lottery mediocrity.
No franchise is going to tank for 2 or 3 years straight in order to get a #1 pick, especially considering they would have no way to know who would be available that far out. So any team that ends up in the top 3 or 4 will have legitimately been bad for a majority of that time frame, even if they did choose to tank near the end of the current season.
Wake up NBA. It's time for a change. Doing so will help alleviate the ever present conspiracy theories that surround the current process and align yourselves with every other major professional sports league. The NFL and MLB don't seem to have problems with franchises losing on purpose. Start policing your league better.