zaterdag 8 mei 2021

The TCEC 21 superfinal book, by GM Matthew Sadler and Jeroen Noomen

I am excited to announce that the TCEC 21 superfinal book has been made in cooperation between chess Grandmaster Matthew Sadler and myself (Jeroen Noomen). Matthew is a well respected Grandmaster and the co-author of the great book "Game Changer", together with WGM Natasha Regan. It was an honour to get Matthew on board and I am very pleased with the result!


Here is the most important information about our joint effort:

  • The TCEC 21 superfinal book was mostly completed in April 2021. Both Matthew and I have chosen 25 lines, which will be played alternately. Matthew's lines are #1, #3, #5 and so forth, my lines are #2, #4, #6 and so forth. The lines are mixed, which means that lower book exits are mixed with higher book exits. I chose to mix the book exits, as the experiment with a low-to-high exit in season 20 led to a lot of draws in the first half of the superfinal.
  • To determine the book exits we used Leela Chess Zero and Stockfish. All lines typically have a LC0 book exit between +0.30 through +0.50, with a few exceptions. Of course the book exits at TCEC will be different, because of much faster hardware and different Leela and Stockfish versions. 
  • As usual, all important openings will be played; just like in the previous three TCEC superfinals there will be a lot more risky opening lines compared to TCEC 16 and before. This is necessary to avoid an excessive number of uninteresting draws. Statistics of the previous two superfinals show that a Leela book exit below +0.30 is an almost 100% certain draw. 
  • The chosen lines typically have a length between 3 moves and 13 moves; there are five lines which are 3 moves long and there are three lines which are 13 moves long. This time some openings will be played more often than you are used to in previous superfinals. 
  • Average move length is 6.84, which is is comparable to the TCEC 20 superfinal.
  • There are sharp lines in the set, as well as positional linesmore complex lines, lines with opposite castling ("SALC", i.e. short and long castling), dubious lines, lines with an imbalance in material and gambits. In my (Jeroen) selection I used a couple of lines of Stefan Pohl's "Unbalanced Human Openings".
  • As I mentioned previously, I now prefer 1-0 1-0 results over two straight forward (i.e. boring) draws. In effect the result is the same: 1-1. But two wins give more excitement. The super solid openings played by today's top Grandmasters are a certain draw in today's engine chess, hence they are not suitable for TCEC superfinal purposes.
  • We have avoided positions that could lead to many exchanges, as well as positions with a symmetrical pawn structure and positions that could lead to easy wins for the side with an advantage. The last aspect is becoming more and more difficult, with strong hardware, a long time control and engines being so strong. Of course risky lines means that the chance of 1-0 1-0 is increasing.
  • What do I expect? 20 wins is the minimum I'd like to see, but of course I hope for more wins. In my humble opinion I think that the TCEC 21 superfinal could be the most exciting superfinal ever!

ECO code distribution
ECO A: 10 lines
ECO B: 16 lines
ECO C: 10 lines
ECO D: 8 lines
ECO E: 6 lines

Move length distribution
3 moves: 5 lines
4 moves: 7 lines
5 moves: 4 lines
6 moves: 12 lines
7 moves: 2 lines
8 moves: 7 lines
9 moves: 5 lines
10 moves: 3 lines