How to test whether the RNG that you are playing is pure random or not?

[albalaha]

Dear Friends,
          I openly invite all you guys and gals to give your valuable inputs upon this topic which every roulette player needs to know. Please make us understand in easiest language possible.

[Proofreaders2000]

Just check the past spins of several live wheels and check the RNG in question.  If the system does well with the live wheels and doesn't do well with the RNG, I would suspect that RNG.

[mr.ore]

You should never see same sequence of four numbers in 15000 spins twice. Probability of any such sequence is p=(1/37)^4. We might start tracking after first observation of some sequence, and z-score for one appeareance in 15000 spins is (1-n*p)/sqrt(n*p*(1-p))=11.08. It is practically impossible to reach that z-score, it should be between +-6. I would say +-7 according to my fair rng experiments. 11 is way too much, it is more than seeing 99 reds in 100 spins, which has z-score 10.07. For 30000 spins z-score is 7.77, which is probably still too much, but I would say it is edgy, near to the "near impossible" +-6.8 which I know that happened.