Christopher Yoo, Dublin, is one of a handful of Americans to become a grandmaster (GM) before his 15th birthday. He might have become a GM much earlier, but he did not play in tournaments for 14 months because of the pandemic.
In February 2019, he became the youngest player to ever earn International Master in American history.
Yoo earned all of three of GM norms in holiday tournaments this year: a Memorial Day weekend tournament, a Labor Day weekend tournament, and a Thanksgiving week tournament.
A GM norm is a high level of performance in a chess tournament that fulfill FIDE’s strict criteria; for instance, the entry must include at least three GM titled players from different countries playing over a minimum of nine rounds.
In December, he met his final requirement, obtaining a FIDE rating of at least 2500, in a tournament at the Marshall Chess Club in New York City.

Yoo is being trained by US Super Grandmaster, Sam Shankland, rating 2717, of Walnut Creek. (Diablo Gazette featured Shankland in the January 2021 edition.) Shankland had this to say about Yoo on Facebook.

“From the moment I met Christopher Yoo, I knew he was an exceptionally talented kid, and one with a huge passion and love for chess. He spent countless hours tirelessly working in my training room. When the pandemic hit, all tournaments were cancelled, and it seemed like his career would have to take a pause. Not for him. We moved our training online.
“When tournaments finally returned, it was like releasing a tiger into a world of turkeys. He ripped through the ranks, and December 12, he became my first student to reach the pinnacle of chess excellence and became a grandmaster… I could not be more proud.”
Yoo submits his chess compositions (puzzle above) each month for the Diablo Gazette readers to enjoy for which I am deeply honored.


by Christopher Yoo

Hint: Underpromotion
1.e8=N! This is the only move to stop Qxg7 mate. 1…Qxe8+ 2.g8=N+! White must check, otherwise Qe5 is possible followed by mate.
2.g8=Q ?? Qe5+ 3.Qg7+ Qxg7#
2…Kg6 Now it looks like we can promote to a Queen and win the game, but there is a catch.
3.b8=B!! Two knight promotions and a bishop promotion! With a8=Q coming Black can resign.
3.b8=Q? Qe5+! 4.Qxe5 Stalemate!
3…Qe5+ 4.Bxe5+- No stalemate