Opening selection TCEC 17 superfinal

Here are Jeroen Noomen's comments on the opening selection for the TCEC 17 superfinal:

"Here are the most important details regarding my selection of the openings for the TCEC 17 superfinal:

• The book was completed in October 2019 and hasn't changed since then
• All important openings will be played
• The chosen lines typically have a length between 1 move and 12 moves; there are two lines which are only 1 ply (i.e. the first white move only), there is one line with 15 moves of book
• Average move length is 6.24, which is the lowest in my TCEC superfinal career
• There are sharp lines in the set, as well as positional lines, more complex lines, lines with opposite castling ("SALC", i.e. short and long castling), dubious lines, lines with an imbalance in material and gambits
• Some lines are borrowed from previous superfinals, they can be the same, somewhat shorter, or longer, if necessary
• The complexity of a position is one of my main selection criteria, i.e. most pieces are still on the board and there should be a lot of play left, with a reasonable chance for a decisive result
• In each line one side typically has an advantage, so each engine gets the chance to push for a win, while in the return game it has to defend the weaker side
• I have avoided positions that could lead to many exchanges and/or have a high draw rate, as well as positions with symmetrical pawn structures and positions that could lead to easy wins for the side with an advantage. I also have avoided 'easy', very solid, classical positions, in which there is almost no chance for the engines to go wrong and where the expected draw rate will be very high (>90%)
• Note: I haven't taken into account the TCEC hardware upgrade with this opening set, this might lead to a slightly higher draw rate than usual. Still I hope that we get 15-20% wins

ECO code distribution

ECO A: 9 lines

ECO B: 15 lines

ECO C: 10 lines

ECO D: 5 lines

ECO E: 11 lines

Distribution of move length

1 ply: 2 lines
1 full move: 2 lines
2 moves: 1 line
3 moves: 5 lines
4 moves: 8 lines
5 moves: 4 lines
6 moves: 6 lines
7 moves: 6 lines
8 moves: 2 lines
9 moves: 6 lines
10 or more moves: 8 lines

A personal note

My sources to select openings for the TCEC superfinals are: GM games, correspondence games, databases, chess books, theoretical websites and my personal opening experience. I prefer lines that have a rather low draw rate in correspondence chess, i.e. preferably 50% or lower.

Personally I am a big fan of original, enterprising, lively, complex and non-standard play. In my opinion lines in this category can lead to far more interesting games than in the usual solid, classical stuff. Hence my opening selection reflects that preference.

Nevertheless, my picks will also always include well known opening lines, as long as they don't have a high chance of a draw. Please note that simple, classical, open and standard opening positions just have a very high chance of a draw, especially under TCEC superfinal conditions and with the TCEC hardware upgrade. We want to avoid >90% draws, therefore I exclude such lines from my selections. I understand that might not be to everybody's liking, but I'd say: if we have a lot of exciting games, this is the way to do it!

So: have fun! I hope you enjoy the games and we will see lots of exciting chess and dramatic turn of events, like we had in all previous superfinals!"