Based on: Josh Waitzkin Chessmaster Strategy Section 6 "The Art of the Trade." A video can be found here.
[Event "From Josh Waitzkin Chessmaster Strategy Section 6 'The Art of the Trade'"] [Site "?"] [Date "????.??.??"] [Round "?"] [White "-"] [Black "-"] [Result "*"] [SetUp "1"] [FEN "r2q1rk1/p4ppp/1p2p3/2p5/2Pp4/PP1Pn2P/3QPRP1/RN4K1 w - - 0 1"] 1. Nc3
Josh says "2 possible solutions" are a4 and Qc1. Technically, he doesn't say they are the only possible solutions.
My thought is to play Nc3 in this position. The chess.com says engine says Nc3 is the best (as in not unique) move.
- Actually, I probably would've done something like b4, but Josh really said that one has to calculate several moves ahead. So, after some deep calculation, I came up with Nc3. I figure the idea is that you realize that black's knight has only 1 defender and then you calculate this counter-intuitive move of seemingly hanging your knight to see if you can really pull off this knight exchange (if black were to attempt to exchange), among others.
- It turns out Josh didn't even seem to do calculations with either a4 or Qc1. He just laid out plans assuming Black wouldn't make any move.
Actually, is Qc1 is merely "good"? 3 of the best moves that the chess.com engine says (either by saying the move is best or by telling what is an alternative) are Nc3, Qa2, and a4. Is Qc1 strictly inferior to Nc3, Qa2, and a4, and, so, Josh is actually wrong here to prefer Qc1 to a4?
1.1. Josh says a4 weakens white's pawn structure. Good point, but I don't know. The engine says Qc1 is just 'good'.
1.2. Well I think the only 2 queen moves here are Qc1 and Qa2. I guess Qa2 is more active than Qc1. I don't know.
1.3. Another thing to note: Maybe Josh mistakenly said Qc1 instead of Qa2. After this correction, perhaps we can then talk about a4 vs Qa2 and then say Qa2 is better.
Wait so what exactly is the calculation here? I was expecting we do (WOLOG the Qc1 thing) Qc1, think of black's move, do a response, etc. In the end Josh just showed how the white knight could go Nd2 to Nf1.