How small can a functional repertoire be?
Some of us are busy or lazy enough to look for opening repertoires that require as little learning and maintenance as possible. But how much (or little?) knowledge is the actual minimum? There probably is a correct answer somewhere but it's constantly changing as opening theory is developing. If you only consider the amount of available GM-praxis you can reach "a playable middlegame" with very little preparation. One solution could be this:
- Black versus 1.d4: 1...c6 2.c4 b5 - a system occasionally employed by GM Rogers.
- Black versus 1.e4: 1...c6 2.d4 Na6 (or 2...b5?!) - a system occasionally employed by GM Miles.
- White: 1.e3, hoping for 1...e5 2.Nc3 d5 3.Qh5 - the Mexican Attack which has a certain surprise value.
The main problem with an approach like this is that you will rarely get an advantage with White and will have to struggle for some time with Black. It must also be said that you give your opponent so much freedom to choose his preferred set-up that you can hardly expect to be playing the game on your home ground. If you are looking for "+=" with White and "=" or "unclear" with Black you will have to devote slightly more time to your preparations.
So if you are looking for an easy solution, these are my recommendations:
Here we either are looking for an opening starting 1.d4 or 1.e4 but deviating on the second move (1.d4 d5 2.Bf4!? / 1...Nf6 2.Bf4 are my personal favorites) or an alternative first move which still restricts Black's choice - possibly the King's Indian Attack: 1.Nf3 followed by 2.g3, 3.Bg2 and 0-0. A move like 1.b3 or 1.g3 may take your opponent out of the book quite quickly but for yourself to be properly prepared you simply have too many options to consider - not only 1...d5 and 1...e5 followed by different development schemes - but also 1...c5, 1...f5, 1...Nf6 etc.
Black versus 1.d4:
My suggestion here is some variation of the Dutch (1.d4 f5). Possibly it's not a good way to fight for straight equality but chances are good to reach an unclear position. I am not yet decided about which sub-system yet but possibly the Classical is a good candidate.
Black versus 1.e4:
Here my favorite is the Scandinavian (1.e4 d5) . The theory is expanding and actually there now is quite a lot of theory. But the important thing is that Black makes most of the choices and to some extent can decide whether he wants a sharp or a solid game.
Any alternative suggestions?