Well, in any country you have a lot of incentive to get involved with the government that is why GR is important for multinational companies. Government often brings a lot of money (Tesla, SpaceX) and it may also create a lot of problems (GDPR). Putin connection is the best form GR in Russia. Melnichenko on that graph is a clear indication that it wasn’t a necessary condition (he was neutral to Putin and stayed rich). Khodorkovsky is an indication that you couldn’t be against Putin and stay an oligarch. I am not expert, I just tell you more information will be better for a bigger picture.

Think about this. There is a regime change (new government is not communist), many people on the list will try to create good relationship with new government, so some oligarchs (those who succeeded) will become even richer (longer existence, longer/better GR, more money). However, their wealth would be possible to decompose into several parts: Yeltsin effect, Putin effect, New government effect.

P.S. GR doesn’t mean corruption per se. GR has legal forms as well, although current Russian GR is mostly corruption

Okay. Your definition oligarch indicates connection to Yeltsin and maybe Soviet regime (average Ivan didn’t privatize big companies). So, what graphs says people with connection to Putin and who are oligarch means that they were in good relationship with government in multiple regimes across time. In other word, good GR across multiple years/regimes means more money. Putin has been in power for 20+ years. So, to indicate Putin effect you may need show how net worth of oligarchs changed during 90s (Yeltsin effect) vs post 2000 (Putin effect). An obvious case that you will find is Mr. Khodorkovsky who clearly outperformed his peers during 90s and he was totally destroyed in the new century. The second case that can be interesting is pure Putin oligarchs, so they created their wealth during Putin’s era with a big chunk of revenue or funding coming from government.

How do you distinguish between oligarch and billionaire? First, you need to prove the difference or introduce a definition. Or just use billionaire who are Russian citizens at the moment.

Secondly, you need to provide a definition of the link between oligarch and Putin/government. If it is a quantifiable measure better to use scatter plot. If it is not quantifiable (e.g. friend, ex-classmate) then some labeling will help.

Right now, it is closer to Russian propaganda graph that proves what you want to prove. It can be correct, but it is not how it should be done.