Precision - Why play it?

As some background, I grew up playing "standard american" (family gatherings since I was about 8), learned 2/1 in grad school and played it for about a dozen years (and still do with some partners), and decided to play precision with my main partner about 8 years ago.

Some benefits and drawbacks of precision are rare and theoretical, and others are frequent and important. I'm going to start with the frequent and important ones, and trail off somewhere down the line (avoiding the "gee, has that happened in the past 3 years" type).

1. The main advantage, and the main reason we play the system, is that it allows us to be aggressive with light openings. Our style is to open ALL 11-point hands and many 10-point hands. (Well, almost all. I'll occasionally pass with QJxx Qxx QJx QJx.) In "standard" systems, opening with light values is dangerous because the forcing opening is 22+ points. As responder with a random 6 or 7 count, facing a partner who might have 21 points for their 1-level suit opening, I must bid something -- and now we almost always end at the two level, and occasionally the three level. If my partner can have random 10-11 count, that can be too high, especially if there's no fit. With precision, opener is limited to 15. I can comfortably pass with those misfit hands as responder and stay out of trouble.

2. A corollary to #1 is that responder can jump to game (1M - 4M) with a huge range of hands -- essentially zero to about 13 or 14 points. This gives the opponents a big problem. When the bidding goes 1S-P-4S to you and you hold a nice 15 count with hearts, what do you do? Well, that depends on what responder can have. Against standard opponents, you can usually act. With a 13 count, or even a big fitting 10 count, responder cannot raise to 4H: there might be a slam opposite a 20-21 count opener. The raise to 4H is almost always pre-emptive, because with a good hand responder will make a more constructive bid. With your strong NT opener, you figure your can set 4S, or have good hope of making a heart contract. Against precision opponents, you can run into a buzz saw: 12 points opposite 13 points, with 4S cold and 5 of anything your way down a bunch, usually doubled by responder. I can't count the number of times we've scored -100 or -200 vs. a cold , 450, 620 or 650 the other way because of this... or a very nice +500, +800 or +1100 when they didn't take us seriously.

3. Opponents (especially good ones) will compete aggressively against your strong opening and your poorly-defined 1D opening. This is an important drawback, and it's critical to have discussions and agreements about the most common special defenses: Mathe and transfer overcalls. Whatever your methods, try to double them whenever you can, especially over 1C when responder is relatively weak -- some people will interfere with total crap just to test you, or because they think that's what you have to do against precision.

There are many more impacts, but these are the most important. If you decide to try precision, I would give it at least 6 months of weekly play -- it takes a while to get the kinks out. In my experience it works best if your style is to bid aggressively; if your style is sound openings, it probably isn't a good fit (although it can be beneficial to learn the ins and outs of the system in order to better defend against it).

By Jeff Rawlings (source: Quora)