I'm surprised no one has mentioned drugs such as modafinil, which is used to treat narcolepsy. In a healthy person, I've read, modafinil boosts alertness without the jitters and faster heart rate that come with caffeine, dexedrine et al. Back then, playing regularly, I was a middling B player; I suspected that with an expert partner and a supply of modafinil I could probably make the finals of the Blue Ribbons. Several top track athletes got suspensions not long ago for taking modafinil, which is on the banned list. I'd be more than a little surprised if no bridge pros are taking the drug or something similar. The workaday traveling pro playing 2-3 sessions a day several days a week may have a hard time resisting the temptation. And at the moment there are no professional repercussions (and I'm not saying there should be), so why not give in?