This game is annotated in “The Test of Time” by Kasparov. I did a sort of “Stoyko” analysis of this position, but not really because there is no need for fantasy analysis as the position is very concrete. It felt like I studied this position for 30 minutes, but it was probably closer to 45 minutes.
All kinds of lines, I was completely amazed by the grandeur of Kasparov’s conception. My final conclusion is that b4 by White is simply a mistake. I didn’t even look at the rest of the game! Here is what I was looking at, Kasparov says “Things hardly would have changed by 20.Rfd1 Rfd8, 21.b4 Nxc3, Rxc3, 22.d4!” and so I analyzed this position, all of the lines, and Kasparov is right it is good for Black after b4, was just so hard to believe and OTB most people try to avoid complications that are wide/many sidelines.
The line given in this note is more complicated than the game continuation where Black has an easy ..Qd7 out. In the line given above, sometimes Black plays ..Bxf3 followed by ..Qb7 and sometimes doesn’t. Taking away a defender of d1 at f3 allows for c5 pawn recapture to pin a Bd4 to unprotected d1. There are also longer lines involving a back-rank check. Kasparov didn’t like his ..Qc7 so much, but he made it work.
One other tidbit that I want to add to when I play OTB from now on is to state a definite conclusions to myself as to why I don’t like a line. It’s too easy for me to calculate, then forget and ten minutes later I am re-calculating that line because I had forgotten why I didn’t like it in the first place, and then actually miss the move, the reason why I didn’t like it before. I am still doing that too often, and in many games it seems. It’s even easier to make this mistake in G/90 because there are often more distractions than one would have when playing in a hall where everyone is just playing chess, and the importance of time becomes even more exaggerated.
Also, here is what happens thinking during a game. “Okay, that line surely sucks, definitely I will play this other one!” Then it’s like “Well, what if he simply plays this and that, surely this must be good for him, I don’t have time for this maneuver and am actually making his position better!” then “Okay, now why was that first move I had looked at so bad after all? You know, the move I had forgotten all about because surely I would never play and need to remember my analysis, yeah that move. Okay then, time is running short, I’ll throw him off by going with that first move that I thought/forgot why was bad. Doh!” If only I remembered my conclusions, I should be able to quickly find and settle on a third candidate move, at worst.