Personal slot RTP and meaningful sample size

I have been looking at exported slot histories and grouping the results by game. Over shorter periods the personal RTP can sit far above or below the published RTP, which is expected, but it raises a practical question: is there any rough number of spins or total wager at which comparing a player's result with the theoretical RTP becomes statistically meaningful? Also, should bonus buys be separated from regular spins when making that comparison, since their cost and payout structure are different?

I'd say somewhere between 10,000 and 100,000 spins you might be getting an estimation of your RTP. But 100 spins may just wind up being 50% RTP without the Bonus rounds.

Usually you need at least 10,000,000 sims to get within 0.1% of the true RTP. Depends on the volatility of the machine.
Maybe a few hundred thousand could get you within 1%.

The answer depends on the variance of the game in question. Here are my quick estimates:

You need 9,604 coin flips getting paid 1:1 to be 95% confident that your result is within 1% of the expected breakeven outcome.
If you are rolling one die and getting 5:1 for a 6, you need 341,880 rolls to get within 1%.
If you are rolling two dice and getting paid 35:1 for boxcars, you need 1,344,560 rolls to get within 1%.

The variance of most slots is around 40, which is a bit higher than the 35:1 boxcars example. Some volatile slots have a variance of 60, 80, 100, or even more. There are a few lower-variance slots out in the wild, but you need many millions of spins on a typical slot to get an estimate of RTP to within a fraction of a percent. Testing labs can do many millions of spins. It is not easy to do it in real online casino play.

I did 470K spins on one particular slot over the course of 20 days in June and had an actual RTP slightly more than 1% above expectation. This was about 3K spins per hour, so almost 160 hours of play.

Quote: harris

Usually you need at least 10,000,000 sims to get within 0.1% of the true RTP. Depends on the volatility of the machine.
Maybe a few hundred thousand could get you within 1%.
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I agree with your estimates. It is really pointless for civilians to try and verify the RTP for each game they play. It is more useful to evaluate your W/L after a year or more and see if your actual RTP is consistent with the weighted RTPs of the games you play. I am thrilled by my actual realized RTP, but then I play a lot of very high RTP games.

Quote: harris

Usually you need at least 10,000,000 sims to get within 0.1% of the true RTP. Depends on the volatility of the machine.
Maybe a few hundred thousand could get you within 1%.
link to original post

I think you really need to take into consideration the frequency of the large jackpots. A game like Megabucks the jackpot symbols will only align between 25 million and 50 million spins. It was so much easier before the Telnaes patent.