CCC13 Shapes

In last week's engine post, TCEC S17 L1 Finished; CCC13 Announced, I noted,

CCC: The site has released plans for CCC13 in the form of a spreadsheet and a graphic. The format is like nothing we've seen before and will take more time to study than I have today.

While it might be useful to summarize all of the different CCC formats since the first season (CCC01), I'll have to limit this post to the two most recent seasons. In TCEC Cup 4 Finals & CCC11 R1 Underway (October 2019), I listed the CCC11 'format for each stage of the competition':-

Qualification : 12 engines, 2 rounds [CCC10 places 1-3 and four others qualify] • Round 1 : 12 engines, 2 rounds [Places 1-8 advance] • Round 2 : 8 engines, 3 rounds [Places 1-6 advance] • Round 3 : 6 engines, 5 rounds [Places 1-4 advance] • Semifinal : 4 engines, 12 rounds [Places 1-2 advance] • Final : 2 engines, 75 rounds

CCC12 used a more straightforward knockout format; from TCEC S17, CCC12 Both Underway (January 2020):-

[CCC12] uses a format not seen in any of the previous CCC seasons • 18-engine single elimination; 200 games per match

The chart below, which is the left half of the CCC graphic mentioned above, shows the CCC13 qualification phases.

The related CCC spreadsheet includes an introduction with some important numbers:-

CCC13: 'Shapes' • Engines: 15 • Games: 2504 • Total time: 35.9 days

As for the event itself, first there will be three co-equal preliminary stages (A, B, C):-

Pentagonal: Five engines each; 20 rounds; Top two advance to 'Heptagonal'; Third place to 'Triangular'; Openings: Popular Chess.com openings (6 ply)

This will be followed by an intermediate stage to give one third place finisher a second chance:-

Triangular: Three engines; 50 rounds; Winner advances to 'Heptagonal'; Openings: Gambit Book

The six qualifiers from the three 'Pentagonal' round robins join the winner of the 'Triangular' round robin:-

Heptagonal: Seven engines; 12 rounds; Top four advance to 'Semifinal'; Openings: Gambit plus Popular book

Two engines will qualify from the 'Semifinal' to the 'Final' 200 game match. It's not clear how the 15 engines were distributed over the three 'Pentagonal' events, but Lc0 , Leelenstein , and Stockfish are playing in the A, B, and C groups, respectively.