The American Cup is now a couple of days in and today we had our first taste of the playoffs, including one match that went all the way to Armageddon between GM Fabiano Caruana and GM Jeffery Xiong.
The following tweet was posted by the Saint Louis Chess Club and sort of explains what happened at the end of the game. Remember the time control for the Armageddon games is 5-minutes for White, 4-minutes for Black, with a 2-second increment in effect after move 60.
Check out the dramatic final moments in the Armageddon game between GM Fabiano Caruana & GM Jeffery Xiong – #TheAmericanCup https://t.co/8IHb6krijC pic.twitter.com/BOajAqJksP
— Saint Louis Chess Club (@STLChessClub) April 22, 2022
There are two moves in the PGN that were not really part of the game, 60… Kc3 and 61. Kg2, because Xiong “flagged” before he completed the move 60… Kc3.
What happens with increment time controls is that you should always receive the increment at the start of the time control, or a time period that has increment.
For example, at the start of a G/90;+30 time control, your starting time will show as 90:30 on the clock because you get the 30 second increment for move 1. This is exactly the same for the Armageddon time control we have, you will get the increment ready for move 61, assuming you complete move 60 in time.
If you watch the video closely, you’ll see that Caruana receives the 2-second increment after he completes the move 60. Kh3. This is what is supposed to happen, ensuring he gets the increment from move 61 onwards. However, Xiong doesn’t complete his 60th move before his flag falls and therefore the clock freezes at that point, which it should. The moves completed after this happens do not affect the remaining times on the clock, so when Xiong completes 60… Kc3, because he’s already flagged, the clock doesn’t add any increment. The same with Caruana’s 61. Kg2.
Bad news for Xiong, but a perfect learning opportunity for arbiters to understand how adding increment mid-game works.