Multiple control groups will highlight the degree that a result doesn&#x27;t have statistical significance yet. We know that peeking is a problem[1], e.g. you peek and see that B is outperforming A by 4% you might be more inclined to stop than if you saw that <i>A is also outperforming A by 4%</i>; it makes you stop and think.<p>Re: N buckets: you&#x27;ll get diminishing returns and it will take N times more data points to get a statistically significant result in any bucket.<p>[1]: <a href="http:&#x2F;&#x2F;www.evanmiller.org&#x2F;how-not-to-run-an-ab-test.html" rel="nofollow">http:&#x2F;&#x2F;www.evanmiller.org&#x2F;how-not-to-run-an-ab-test.html</a>