Wednesday, 30 October 2019

2019 1+0 Candidates Recap & Announcing the Final

The 2019 Bullet Crazyhouse World Championship Candidates are completed after a summer hiatus and the Grand Final between IM opperwezen (Vincent Rothuis from Holland) and JannLee (Justin Tan from Australia) is now underway. The first session of the Final happened last Saturday at 1200UTC with 30 games of 1+0. The second and third sessions will be on the 2nd and 9th November 1200UTC with a further 30 and 40 games respectively to complete the 100 game match. All games will be played on lichess.org and can be watched on the Lichess TV channels of the respective players as well as being streamed by JannLee (without commentary), Mugwort and okei on Twitch. After the first session opperwezen leads 18-12 with 50.5 being the target for victory. This post is to report how we got here since our announcement of the eight Candidates back in the spring.

The first match of the Candidates was on 21st May between the reigning 2018 World Champion in 3+2 crazyhouse IM opperwezen and the tournament organiser and 2018 CWC Candidate FM littleplotkin (Mark Plotkin from Canada). Opperwezen proved too strong and went on to win six out of his seven matches over the subsequent 31 days, again the first to complete all his matches as in 2018. He only lost to JannLee 14-16. In total he racked up 145 game wins out of 210 games (69% win rate) all but guaranteeing himself a spot in the Final which could only have been denied if two other players scored a greater total of game wins. Despite most matches being completed within 7 weeks as planned, OTB tournaments and the birth of Jann's second child put a stop to the action for a couple of months and the last few matches were not completed till October. With the final match of the Candidates, JannLee overtook opperwezen's game total by one game, scoring 146 game wins, along the way also scoring the biggest demolition of the round robin with 26-4 against VariantsOnly. We are in store for a great Final! Moreover, the winner of the Final will play an exhibition match with a separate prize fund with Jasugi99 (Janak Awatramani from Canada, formerly known as TwelveTeen aka cheesybread on FICS, 12teen on chess.com).

In third place on 116.5 game wins was chickencrossroad (who famously withdrew from the 2017 Candidates making way for opperwezen to take his place after an intensive qualifying tournament against all-comers). Apart from JannLee and opperwezen, chickencrossroad beat everyone else. In fourth place was penguingim1 on 109 game wins who beat everyone apart from Jann, opper and chicken, and in fifth was mastertan on 96 game wins who beat everyone apart from Jann, opper, chicken and penguin. In 6th was blitzbullet beating littleplotkin in 7th who in turn beat VariantsOnly in 8th, but VariantsOnly saw off blitzbullet in his final game, so the bottom three all won one match. Below is the full table of results and on the second page of the Candidates spreadsheet you can also find all the game links and streams. Thanks to TheFinnisher and LegionDestroyer for helping keep this updated!

See you on coming Saturdays at 1200UTC to watch the Final. To whet your appetite, here are a selection of 40 puzzles of various difficulties which you can either solve in your head, or if you prefer play out against the engine in a Practice with Computer Puzzle Study on lichess. There is also a solutions study. For a video recap of the Candidates (don’t look if you want to enjoy the puzzles below), check out part 1 and part 2 of the Highlights video. Coverage of all the 2019 CWC 1+0 matches (including my own coverage of week 1 of the Finals) may be found in the 2019 CWC 1+0 playlist with 39 videos to date.

Level 1 (1800): Improver

Level 2 (2000): Intermediate

Level 3 (2200): Expert

Level 4 (2400+): Potential Candidate

Instead of solving these in your head, you could also try to play out your solutions against an engine.

Check out the variations here.

We leave you with Jann's own recap of the Candidates and looking forward to the Final:

Keep playing crazyhouse and supporting the community!

—okei

Thursday, 3 October 2019

Back-Rank Mate

One of the most important mating motifs in crazyhouse (as in chess) is the back-rank mate. Unlike in chess, checks can be blocked in crazyhouse using pieces in hand, so getting the back-rank mate to work is a little more intricate. The final checkmate must either
  • be delivered by a rook or queen adjacent to the king,
  • smother the opponent king e.g. with a pawn on the 7th rank, or
  • exhaust the opponent’s pieces in hand.
These three can be illustrated in the following gif showing three possible continuations in a winning endgame between catask and CrazyAraFish (the actual game followed the second variation).


The best way to learn crazyhouse is through practice. So the following is a study of 31 back-rank puzzles carefully chosen to train different back-rank mating patterns, and getting progressively more difficult so despite being designed with beginners in mind, hopefully even advanced players can enjoy it. Play against the computer and see if you can deliver mate!


Understanding this mating theme will also help when you are on the defending side and need to recognise if you are susceptible to a back-rank mate yourself. If you are ready to see the solutions, they can be found in the following solution study:


If you prefer to sit back and watch someone else solve these puzzles live, then here was the live stream with the-lone-wolf where we explain the puzzles and the-lone-wolf solved them live on stream as well as contributing the final puzzle:



—okei

Acknowledgments: Many thanks to lishadowapps for having created the PGN Editor with which the gifs were made in this and my previous blog. Many thanks to the-lone-wolf also for helping to create the instructive video.

Season 8 of the ZH League

Season 8 of the crazyhouse team league played on lichess.org was the toughest ever with former and current world champions JannLee and IM ...