Yes, you are actually correct. I have heard of situations where someone (a gambler) says that they become more active and alert after they take some alcohol, and that's when they can do something very well. I kind of believe that it's true, but not for every occasion. Like in gambling, if your mindset is not stable, it's going to lead to making some kind of mistake that will either result in more losses. The person can either get emotional because they are losing their bet or they might want to chase their losses, which can contribute to more losses.
I don't know how much of it is true. It's hard for me to believe. But again, everyone is built differently, so people have different tolerances for alcohol consumption. One may have one or two drinks and black out. One may drink an entire bottle without a blackout.
But again, consuming alcohol or not one should be focused when gambling. It's a rule one must follow. Because alcohol can affect one's judgment, mood, and mind. It's not advisable to work, play, drive, or do any kind of physical activity while drinking.