Selective vs. Non-Selective Beta-Blockers
There are actually two different classes of beta-blockers.
"Selective" beta-blockers work on beta-1 adrenoreceptors, which control heart rate and force of heartbeat. "Non-selective" beta-blockers work on beta-1 adrenoreceptors and beta-2 adrenoreceptors, which control the relaxation of smooth muscle.
So you can imagine that each would effect game play under pressure quite differently. Obviously the "non-selective" would have a much more calming effect than the "selective".
I used to take Propranonol for both over-active adrenaline and as a migraine preventative, then later in life because of hypertension. I can say without question that it did have a calming effect on me BUT... I would not recommend it unless medically necessary due to many side effects (one of which can dampen a romantic evening with the wife/girlfriend/significant other in the bedroom... as well as causing unavoidable weight gain).
After being diagnosed with advanced emphysema, my pulmonologist changed me to a "selective" beta-blocker Metoprolol. I hated the change because I found the "non-selective" Propranonol much more balancing than the "selective"... but if I want to continue to breath then I'm stuck with the later because it's safer. Both cause shortness of breath but the "non-selective" was much worse.
BTW... anyone with COPD who is taking a "non-selective" such as Propranolol needs to change pulmonologist, because a "non-selective" bb will often cause the lungs to relax more than a "selective" bb. The very first thing that a pulmonologist should do is to get you adjusted to the safer of the two types of beta-blockers and then assess your PFT abilities once you have adapted. (I only posted this part because I've read a few comments on AZB from people with COPD that are taking Propranolol).
With all of that being said, if I had a choice... I wouldn't take either just to help my play at the table... even for money. It might help you to relax but it will likely cloud both your focus and also your shot judgement. You will find yourself not seeing the run as clearly as you would without it. A relaxed body means a relaxed mind. Pay attention to Earl the next time you watch him shoot. Does this guy ever look relaxed? He's the most hyper shooter I've ever watched... and most here on AZB would love to have his game.