12/8/2021 – Oh dear! The last door really was a tough cookie. Rarely have we received so many different answers, so we decided to draw two more winners for the day. In the video, we see the details of the solution Kc2, which lay dormant for more than 100 years. Today we have only four pieces on the board, and yet the solution is not crystal clear.

12/8/2021 – After blundering in game 8 of his World Championship match against Magnus Carlsen, Ian Nepomniachtchi also blundered and lost in game 9. Carlsen now leads 6-3 and with five games to go the match is practically over. Wesley So took a close look at game 9 and concludes: "Ian was playing very well early on in the match but ... game 6 was clearly the turning point in this match as before that both players were playing equally well and it seems that Ian was no inferior to Magnus. ... Ian is a great player and even the greatest players make mistakes. Unexpected and miserable stuff happens to us all, and we hope Ian will be able to move on and get his mojo back asap!" | Photo: Wesley So (Archive) | Photo: Lennart Ootes

12/7/2021 – The World Championship match in Dubai might theoretically finish after 11 (out of 14) games, as Magnus Carlsen scored a third victory in four games after Ian Nepomniachtchi inexplicably blundered a piece in an equal position on Tuesday. The challenger now needs to win 3 out of the 5 remaining encounters to take the match to tiebreaks. | Photo: Niki Riga

12/7/2021 – Not quite a London System and not quite a Veresov. The unusually named ‘Barry Attack‘ lies somewhere between the two. Yet another challenging queen pawn system that Black has to prepare for.

12/7/2021 – First, thank you very much for all the answers! We are delighted that this calendar is so well received. Door number 6 proved to be one of the most difficult ones, although the majority were able to find the somewhat bizarre move Kh8. If you thought door 6 was tough already, today we raise the difficulty even more. Good luck!

12/7/2021 – This year, the Dutch National Championship was played in two stages. In the knockout preliminaries four players had qualified for the finals: Max Warmerdam, Robin Swinkels, Roeland Pruijssers, and Hing Ting Lai. Max Warmerdam convincingly won the finals, a double round-robin which was played last week. | Photos: Harry Gielen

12/7/2021 – In queen endgames having the initiative is crucial. In the diagram position it is Black to move and it is Black who has the initiative. But how should he proceed?

12/6/2021 – Christmas trees mixed with chess boards at the 2021 Forester Open. Grandmaster Christopher Repka and International Masters Brian Escalante Ramirez and Viktor Gazik shared $3,224 for first through third places, acquiring spending money for this holiday season.

12/6/2021 – At the halfway mark in the 1969 World Championship between Petrosian and Spassky, the match score was level. Petrosian only needed to draw the match to retain his title, and with his super-solid Petroff it looked like he was going to wrap things up. But in game 17 and 19 Petrosian suddenly switched to Sicilian, losing calamitously. John Saunders retraces the course of the match that decided who would defend the title against Fischer three years later.

12/6/2021 – In the Endgame Magic Show #174 Karsten Müller and Arne Kähler continue to follow the World Championship match and take a close look how Carlsen and Nepomniachtchi played in games 3 to 5 of the match. | You can watch the Endgame Magic Show on-demand with a ChessBase Premium account.

12/6/2021 – Last Tuesday, 30 November 2021, the English Grandmaster Jonathan Penrose died at the age of 88. In the 1950s and 1960s Penrose was the best British player, and he became internationally famous when he defeated the reigning World Champion Mikhail Tal at the Chess Olympiad in Leipzig 1960.

12/6/2021 – The absolute majority of the answers were "B", which proves that you saw a stalemate motif that actually escaped the Komodo engine. Thank you again for the many detailed answers. We'll stay with the engines because the next task could only be solved by Karsten Mueller and Alexei Shirov thanks to "Fritz 3"! Attention, the task is not easy!