The 6th World Chess Software Championship started on July 2, 2016. Seven programs participated in a round robin tournament of seven rounds. The tournament took place at the Leiden University and is organized by the ICGA, LIACS and LCDS. The sponsors are Google, Naturalis Biodiversity Center, the municipality of Leiden, Leiden University, Faculty of Science, ICGA, iSSC, SurfSara, Digital Game Technology and NWO Exact Sciences. It is held in conjunction with the 22nd World Computer Chess Championship, 19th Computer Olympiad and the 9th Computers and Games conference.
Ginkgo – Raptor 0-1
Komodo – Hiarcs ½-½
Shredder – Jonny ½-½
Ginkgo versus Raptor proved that computers know many things and can compute even more. The opponents played a Semi Slav opening in which black castled to the queenside and the center was dominated by dynamic pieces and pawns. Both programs knew that there were many examples of previous games stored in their libraries. At move 22 white played a new move 22. Nb5. Earlier two other moves were played 22. Ne4 and 22. Na4. Apparently the attacked knight is a problem to white. This observation was very well exploited by Raptor. On move 28 (see diagram) it played Rd7-b7 and hit with this move the nail on its top: where should the white knight go and what should be the result? It turned out that there was no better place then Na7 and after 29. … Qb6 the queens were exchanged. However white’s knight problem was not solved and it took him several moves to free the knight. Black spend that time quite well and build up a won position. Although white had the pair of bishops against two knights, it turned out that the two passed pawns supported by the knight was sufficient for the win. On move 47 white agreed with this opinion by sacrificing the exchange in an attempt to prolong the game. Raptor completed the work efficiently and effectively.
The new world champion Komodo had a tough game against Hiarcs in the first round of the WCSC. After an English opening we saw that white’s position had to stand some pressure by the black pieces. By the move 18. … Bf5 black made an attempt to maximize his pressure with a variety of small threats. It was time for white to take appropriate actions. Komodo did so by playing 19. Bg2-e4 (see diagram). Surprisingly this move indeed solved all problems white was facing. After some large sequence of exchanging pieces the position was equal. Although both sides tried to prove that their side was slightly better it was in vain, the draw could not be avoided.
The game Shredder – Jonny was a fantastic fight. After a declined Queen’s Gambit white tried to consolidate a small opening advantage. But Jonny aimed also on advantage and we saw a big fight on a squared millimeter. It looked that black was the more clever collector of small advantages. Jonny obtained some pressure on the white position. However Shredder understood the possibilities of the position quite well and succeeded time and again to reply adequately on the small threats post by Jonny. The diagram position is a telling example. White’s last move has been f3-f4 and now there was a large sequence of moves of which the outcome was a position with limited pieces and clearly drawish. However these players are both fighters up to the very end. For those who like to see the game to its full extend they have to replay some forty more moves in which the value of the game did not change. The draw was deserved result for both sides.
Hiarcs – Shredder 0-1
Raptor – Komodo 0-1
The Baron – Ginkgo 0-1
The second round of the WCSC was remarkable since all three games ended in a win for black. The first one was between Hiarcs and Shredder. They started with a sharp variation of the Sicilian Defense in which both sides had pawn run on opponent king. Mostly the issue is who is the first to bring the opponent king into danger. This game was an exception because both players seemed to be the first. The diagrammed position is a telling example of what was at stake. Black and white pawns intermingle in the front of the white and black king respectively. It was hard to get a correct evaluative answer although the expert opinion maybe a little bit inclined towards black since in retrospect we know that black is the winner of the game. Seen from the diagram position we believe that the outcome will be a win for one of the two. However this opinion disregards the defending power that current programs possess. They have ingenuity and find time and again escapes. That also happens in this game where white was able to reach an endgame of rook and bishop versus a queen with three pawns at both sides. Black played that position very well and won deservedly.
The game Raptor – Komodo can be characterized as weaker player against the world champion. This is a well known feature in the human chess world. World champion Karpov was a chess player pur sang. He did not like analysis he liked to play. If he discussed a game afterwards and his opponent stated that the current position was objectively seen a draw he always invited the player with the words “OK, you think so, but let us play and see what happens.” This is the best characterization of the game Raptor – Komodo. In early midgame Raptor lost now and then a tempo which Komodo exploited to its advantage. However the advantage so gained was not sufficient for a winning position. After a long fight in which Komodo had not reached his aims there was an unequal ending on the board. However equal or not Komodo played on and outplayed Raptor as did Karpov with many opponents. See the diagram position in which the endurance of play is materialized by winning the a-pawn. The conclusion is unavoidable the strongest program has won this match. It was Komodo.
In the game The Baron – Ginkgo the white player started ambitiously and obtained a passed pawn on d6. Was it an asset or was it a liability? If it was a liability could it be made an asset? White worked very hard on answering this question positively. It sacrificed a pawn on f5 and really obtained a nice looking position. Now the question was how to exploit this position. On move 23 there was a decisive moment. White chose for the 23. Rd3. However better would have been 23. b4 or 23. a3 with the goal to answer 23. … a5 with 24. b4. By missing this opportunity black was able to take the initiative in the complex position and slowly achieved the upper hand. That resulted in a deserved win for black.
Komodo – The Baron 1-0
Shredder - Raptor 1-0
Jonny – Hiarcs 0-1
In the game Komodo – The Baron we saw an English four knights opening. This opening always requires subtle treatment. Both sides are more or less at liberty to place their pieces on the appropriate squares. The best strategists have best winning chances. In the game Komodo showed its power. Nevertheless The Baron developed some nice ideas and handled accordingly. It looked that nothing was wrong with his approach although his pieces were not fully harmoniously placed. However next to strategy tactic plays an important role in chess. In the diagram position Komodo found a surprising move, worth to be played by the world champion. Komodo played 28. Rg1xg6. It fully destroys the black position. In the sequel black could have defended better, e.g., by playing 29. … Bxf5 instead of 29. … Rxf5 but this should not have changed the outcome. A deserved win by white.
Shredder – Raptor was an exciting game that started as a Slav defense, Dutch variation. Shredder played rather active from the opening and it looked that he had a clear initiative in his hands. However black found a very good defense line which was based on the activity of it’s a-pawn. By his sharp play black challenged Shredder to go over to immediate action. The two different approaches are seen in the diagrammed position: black has a dangerous pawn on a2 and white has chances along the h-file. The question now is who is first and what is more important, to catch the black king or to promote the black pawn to a black queen. White played very accurately and started in the diagram position 28. Rh2. Black managed to prevent white from mating him but had to restructure its defending position. Still he had his asset on a2. White was well aware this pain in the ass and regrouped its pieces to eliminate the a-pawn. White did so in a very elegant way. On move 45 he simply took the pawn by his rook although its queen was attacked by black. The implicit change of queens ended the black chances completely. White won by following the better concept during the game.
In the WCSC Jonny – Hiarcs is a game which is played under different circumstances than in the WCCC. Jonny is handicapped by 2396 cores. With only 4 cores it is still a strong program as can be seen in this game although Jonny lost. The game started as Queen’s Gambit Declined. Black played fiercefully but Jonny showed its experience and hold its own. Yet the initiative was with black. On move 25 Jonny took the wrong decision (see diagram), it played 25. b4? The idea was based on the cunning move 27. Rb1 of which the program much more than the reality could give him. In the diagram a better change would have been 25. Nxc6. The game progressed with black increasing its threats and opportunities. On move 37 there was no other opportunity for white than to sacrifice a pawn and hoping that the resultant ending would be defendable. It turned out not to be the case and so Hiarcs could add a nice victory on the former world champion to his credentials.
Raptor – Jonny 0-1
The Baron – Shredder ½-½
Ginkgo – Komodo 0-1
In the game Raptor – Jonny, Raptor did not show any respect for the former world champion. Right from the beginning Raptor played a fresh game with fresh ideas and with a large amount of energy. The game is too complex to analyze in this report in detail. Obviously white had much compensation for the pawn sacrificed. Having compensation and substantiating it is not the same and so white suffered from a heavy task which it could not fulfill. Below give a telling example in which white took the wrong path (see diagram). In the diagram black had just played 25. … Rf5 with the threat Rh5. Obviously the position is complex. A possibility 26. gxf3 which does not solve all problems but seems to be actually playable. However white played the wrong move 26. Qa4. In itself the move is understandable but seen from a strategic point white should never move the queen from the scene where the fight takes place, i.e., the kingside. After this move the white chances disappeared. Nevertheless white reached an endgame in which black had not a walk over although it won in the end.
Shredder is a former world champion and thus has proven strength at his disposal. In the same time that Shredder played on his tops The Baron was a runner-up: strong and dangerous for every opponent. In this new encounter The Baron shows how easy it is to make a draw to one of the strongest programs. The simple trick is to exchange all pieces and keep the elementary ending on a draw. This strategy succeeded in the current game. See the diagram and understand that Qxc5 will reach the result described above.
The game Ginkgo – Komodo started as a Dutch game, Leningrad variation. This is a difficult opening, very strategic and full of pitfalls. For Ginkgo it was a chance to visit Komodo in its strongest point, namely strategy. Ginkgo did well in the opening phase and also in the early middlegame phase. It was difficult for Komodo to get contact with the white position. Black tried several things but white had always an adequate answer, at least up to move 31. Then Ginkgo was facing a choice between 31. Kg1 and 31. Kh1. For human beings both had their advantages and disadvantages. For computers matter were more clear. 31. Kg1 was highly to be preferred over 31. Kh1. However Ginkgo played 31. Kh1 and became tricked into a suspicious situation. The move was not a clear blunder but simply a weak move suffering from all kinds of small deficits as is shown by the maneuver 31. … Re8, 32. … Re4. White’s answer 33. h3 was then inviting the black pieces to penetrate the white position. After that move white was lost although took some ten moves before the program resigned.
Shredder – Ginkgo ½-½
Jonny – The Baron 1-0
Hiarcs – Raptor 0-1
In the game Shredder – Ginkgo both programs aimed at a battle in full dress. The first 10 moves went rather quiet then both sides placed their pieces on squares where they could start attacking activities. On move 22 white believe the time is ripe to start a direct fight by 22. Nxf5. It led to an interesting position after 22. … Qxf5 23. Rxe4, Qh3. White was a pawn up but the exchange was still an element of the skewer on b7. The complications that followed were mostly in favour of black although white could stand its own. For one or another reason white found time and again the right moves. This was the basis for his survival. Of course the game continued and several more of such local fights occurred always with the same result. This implied that at least in this game the programs were each other equal. So a draw result was deserved for both sides.
Jonny – The Baron was a game in which Jonny could show all his knowledge of chess and chess play, whereas The Baron was applauding the ideas Jonny put forward. This humble position does not make you enthusiastic for the game and mostly prevent the pleasure in replaying such a game. Right from the beginning Jonny improved its position by nothing else than playing strong moves. On move 32 all white’s pieces were perfectly placed. It was time for the decisive variation to be played. Although the square d5 was defended four times and attacked only two times white decided to play 32. d4-d5 (see diagram), freeing the line for the white queen to f4. The game went on by 32. … exd5 33. Qf4, Kg7 34. h5, h6 35. Nd4, Rg8 36. Bg4, Qb8 37. Re1, Rb7 38. Qc1, Kh7 39. Rxe7 after which the black position collapsed. A nice game by Jonny.
The game Hiarcs – Raptor had a peculiar start 1. a3. Both programs were out of book. What does this mean? They will play on their own intuition. What we saw was a game in which both players showed ingenuity and experience. They arranged the pieces in a harmonious way, rearranged them and formulated new goals to achieve. Around move 40 it was time to force the other to make decisions. Black did so by playing 39. … e6-e5 (see diagram). White replied by 40. f5, Nf4 41. Qxg7. Then it turned out that the black king was save on e7 and later could find a save place at the queenside. Meanwhile the knight on f4 and the queen from c5 reigned over the position. Therefore white decided to sacrifice an exchange in order to get the overarching pieces out of their power. The latter task worked well but the exchange was missed sorely. Black played very well and in an indisputable way it brought the full point home.
The Baron – Hiarcs ½-½
Ginkgo – Jonny ½-½
Komodo – Shredder 1-0
The Baron knows very well that when playing to an opponent with a higher reputation showing activities is important. In chess this is possible by not being aggressive but being determinant in difficult positions. This playing style is what The Baron showed in its game against Hiarcs. In the opening (Caro-Kann) player found their way along the usual paths. Then they started to go their own way. Hiarcs seemed to have the initiative but The Baron was inventive and created counterplay at the kingside and in the center. Hiarcs had to handle new ideas and to insert them in its own plans. That was a complicated task. An example of such task is given in the diagram below. Hiarcs had a good position. For the Baron it was time to become active. So it played natural move 35. d5 and saw that Hiarcs had difficulties to solve the complications. The game continued by 35. … cxd5 36. cxd5, Kg7 37. b3, a5 38. d6, Ref7 39. Re4 and again we were in a position where it is difficult to find the right way. Both programs did so and a little bit later the game was drawn. Thank you for the nice performance.
The game Ginkgo – Jonny started with 1. b3 which implied that there is no much opening theory. Yet the players built up acceptable positions on both sides. Here again we saw that Jonny is severely handicapped by the use of only four cores. The game progressed in a quiet way with some difficult decisions to be made. In the diagram we show you the result of a decision made earlier in the game tree search. It deals with the capturing of h7 by white and a4 by black. Apparently both programs considered it a fair pawn exchange. However the result is that black has a passed pawn and white a knight which is for some time out of play. Nevertheless black was unable to exploit this situation in its favour. After some time the game faced another difficult decision which was solved in the same way so there cannot be a surprise that the final result of the game is a draw.
In a closed Sicilian game Komodo and Shredder were fighting for the first place. From the beginning black tried to keep the initiative. That was a good idea but the result was that black had two pigeon holes in his fortress. One on g5 and one on e5. The pigeon hole on g5 was occupied by a white knight on move 20. The pigeon hole on e5 was occupied by a white knight on move 40. Although they were strategic drawbacks black could live with them. However the most not shootable decision by black was taken on move 37 (see diagram) were it played 37. … Nb3. It was the beginning of a play without knight. This means that as the game went on white, Komodo, played with a knight ahead. In summary with a knight ahead and two pigeon holes to enter the position white should win that game. Black made two attempts to change the course of the game. The first attempt was on move 54 by playing Na1 and the second one was on move 64 by playing Nc1. Both attempts were in vain. It all implies that white won the game.
By this win Komodo was the winner of the software tournament since its leading position could not overrun by another program.
Jonny – Komodo ½-½
Hiarcs – Ginkgo ½-½
Raptor – The Baron 1-0
Jonny – Komodo ended in a draw. It was certainly not a grandmaster draw in the human meaning of the word. It was a grandmaster draw in the world of computer players exciting play inspiring ideas and materially unbalanced positions. All positions are difficult to evaluate in separation. Seeing the game the position form a chain of events. Every event is characterized by the idea of the program. The playing strength of these two program is the top of what the ICGA events have as participants. A most exciting moment is seen in the diagram below. White played 19. exd5 and black answered 19. … Qe5 gaining back the piece or even the rook. That decision is at the discretion of white who took the following line 20. Kf2, Qxa1 21. dxe6, fxe6 22. Bc4, Qe5. No wonder that the game ended in a draw.
In its last round game Hiarcs tried to improve his score by strong strategic play. Having white the program attempted to exploit the initiative. Therefore it build up its position very carefully for the first 20 moves. However black was on its alert and saw what white was doing. At the moment he was able to free himself he took that opportunity by playing 20. … c7-c5. After the exchange of many pawns and piece an equal ending occurred on the board. Both programs continued for a long time but the result was an unavoidable draw.
The last game of the tournament was played between Raptor and The Baron. Both programs would like to complete tournament by a win. They played a quiet opening which is a rather unknown variation of the Ruy Lopez. White was able to place its pieces in a excellent position. On move 13 he saw an opportunity to sacrifice the bishop on h6 for two pawns. However in his game tree that the third pawn was also coming in in addition to positional advantage. The latter element took care for a regain of the piece which resulted in an endgame with a pawn ahead. This endgame was an easy win for white.
The total result of the tournament was that Komodo became winner with 5 points out of 7 games.