Queen Sacrifice by Natalia Vetrova
In addition to being a GM, Krogius is an International Arbiter, psychologist, chess coach, chess administrator and author. I have Krogius' book, Psychology in Chess published in 1976 in which he examines typical psychological oversights made by players at nearly every skill level. Some parts of it are quite interesting, but for the most part, I found it dry and uninteresting.
He won several tournaments, mostly in the Black Sea area and eastern Europe. Krogius played for the Soviet team in the World Student Olympiad in Oslo 1954, where he scored +7 =1 -1 on board three, and won team silver. A late bloomer, Krogius had several failed attempts at reaching the Soviet final and did not make his first one until age 27. His graduate studies were the priority until he finished his doctorate. Eventually he clawed his way up the Soviet hierarchy and participated in seven Soviet finals between 1958 and 1971. In the 1991 World Senior Championship he tied for 3rd-6th places and in 1993 he tied for first with Anatoly Lein, Mark Taimanov, Bukhuti Gurgenidze and Boris Arkhangelsky at the World Senior.
Krogius is a psychologists specializing in sports psychology and he coached Boris Spassky for several years, including Spassky's title match against Petrosian in 1969 and against Bobby Fischer in 1972. He has also served as chairman of the USSR Chess Federation, and co-authored five chess books.
Krogius scaled back his tournament play by the mid-1970s, playing only in occasional lower-level events and began important contributions as an author and at the same time moving into chess administration. He was captain of the USSR team for the USSR vs. Rest of the World match in 1984 and was the head of delegation for Anatoly Karpov's team for the 1990 title match against Garry Kasparov.
You can read excerpts from Krogius' biographical book, especially the Fischer match at Chess.com HERE.
The following game, won by Stein, appears in The World's Greatest Chess Games where it received a rating of 9 out of 15. In the game Stein played an inferior opening line and soon got into trouble and in desperation undertook a sacrificial attack that technically should not have succeeded. But, as is often the case, Krogius lost his way in the ensuing head whirling complications and allowed Stein to finish with a neat Queen sacrifice.
The game would have made good material for Krogius's book because it shows how difficult it is to conduct a defense against a prolonged and vicious attack as well as what happens when you make a mistake...another one is lurking in the background waiting to rear its ugly head.
It was very interesting to go over this game with Stockfish 9 and compare its moves to John Nunn's comments because in many cases the engine disagreed with his analysis. When the book was written the authors used Chessbase for analysis. Engines will be quick to point out tactics, but long range strategy is still something they cannot perform well, but it is the GMs forte, so I think Nunn's positional evaluations are more likely to be correct than Stockfish's purely mathematical evaluation as long as there are no tactics involved.
Sidebar: Kris Littlejohn, a second for Hikaru Nakamura, did the data gathering and analysis. No ordinary off the shelf laptop here! Littlejohn began by building a special computer for that purpose. He would begin work weeks or even months before a tournament as soon as the list of participants was known. Then databases are combed gathering information about lines opponents like to play and then a search to ferret out novelties begins. He uses branching to predict all the possible moves that could be played. The next step is to figure out which moves that opponent would be comfortable with given his historical games. The result is a report of possibilities. Of course it's also necessary to keep current on what opponent's have played to avoid surprises. Consideration will also be given to Nakamura's tournament situation and whether he needs a win or a draw.
When traveling with Nakamura, Littlejohn used his laptop to connect with the big computer back home and he also had a backup laptop available with a chess program just in case of Internet outages.
Littlejohn and Nakamura then go over the report together and Nakamura memorizes the 500-1000 moves, reciting it back to Littlejohn without looking at the board to ensure that he has all the information in his head when he goes into a game. And now you know why we aren't all Grandmasters!!
Engines can process more information faster than the human brain, but there are things computers can't do. Much of chess is intuitive and engines will miss those nuances. That's the reason GMs and top level correspondence players use engines as a starting point, but they are the ones who make the final strategic decisions.