The idea behind this repertoire is to provide a comprehensive response to 1.Nf3. My choice for the first move is 1…d5. The essence of this repertoire is to offer variations that do not transpose into any opening arising from 1.d4, ensuring that any player with Black can employ these lines, regardless of their main defense against 1.d4. The only potential “issue” might arise if White plays 1.Nf3 d5 2.d4. In this case, I need to make a few considerations. Firstly, there won’t be an issue for players who employ the Slav Defense, QGA, or QGD against 1.d4. However, for those who play the Gruenfeld, KID, or Queen’s Indian Defense (or other minor openings) against 1.d4, they have four options against the move order 1.Nf3 d5 2.d4:

1. Study a second opening such as QGD, QGA, or Slav against 1.d4.

2. Start with 1.Nf3 Nf6 and attempt to transpose into the analyzed lines, even though this will not be possible against move orders like 1.Nf3 d5 2.c4 and 1.Nf3 d5 2.g3.

3. Opt for a lesser-known line, meaning that after 1.Nf3 d5 2.d4, explore the options of 2…Bf5 or 2…Nd7. Both are intriguing lines frequently employed by high-level players, providing an entirely independent opening compared to the openings that can arise after 1.d4 d5 2.c4.

4. Play the QGD with Black, where White doesn’t have the opportunity to enter the main Carlsbad line arising from 1.d4 d5 2.c4 e6 3.Nc3 Nf6 4.cxd5 exd5 5.Bg5.