Openings for various levels

It is always a question how much theory one needs for his level. Is 2-3 A4 pages of material too much for 1000-1200? Is 10 pages of A4 too much for 2000? But lets look at that from another angle. Nowadays people play blitz every day. And its good as long it is not too many games per day :). When one lacks opening material, it is possible to encounter unknown positions in every single game! But when one has even a lot of material stored in the computer or even printed out, it is easy and useful to go over it after the games and learn new lines this way. So, don’t be afraid of much material – obviously nobody can remember it all (especially, if one is below 2300-2500). But it will be very useful for your online or tournament practice.