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The problem with this assessment is that computers basically cheat. Carlsen isn't allowed to turn up to a game with an openings book, and some way of looking u

The problem with this assessment is that computers basically cheat. Carlsen isn't allowed to turn up to a game with an openings book, and some way of looking up all possible 7 piece or less endgames.(if I remember correctly), but the computer can. Another way of looking at is that if Carlsen had all that information at his disposal every time he played another human, his rating would be 300+ higher than everyone else as well.

shaggyfrog 13y ago
This is not cheating in any real sense of that word. The computer has that opening book in its memory, so why shouldn't it make use of it any more than Carlsen is making use of his memory? What's the alternative? Harrison Bergeron-style handicapping of computers, to soothe our human egos?
tzs 13y ago
Today's computers would still dominate even if their opening books were taken away. Open book essentially represents a very extensive analysis of one position (the starting position) that has been carried out by humans over centuries. We aren't as fast as computers, but we've been working on this one problem longer and with massive parallelism, and so we've got the main lines covered quite deep. It used to be that most of book went deeper than a bookless computer could analyze in the time available for the opening in a timed game. This meant that a booked up human could steer the game into lines that appeared favorable for the computer when analyzed to the depth the computer could analyze, but were actually favorable to the human when analyzed to book depth. Computers are now fast enough that they can reach or surpass book depth in most lines, making it much much harder for a booked up human to steer the game into a favorable line. As an example of how fast computers are now, I just let Stockfish 4 64bit have a go at the start position on my 2008 Mac Pro (dual 2.8 GHz quad core Xeon processors, without hyper threading). I gave it 3 minutes (3 minutes per move is common in world class chess events). These were the settings: 8 threads, idle threads do not sleep, 8 GB hash table. It reached a depth of 30 ply (44 ply in selective search), and examined 940 million nodes, averaging around 5.3 million nodes per second. (It picked d4 as its move, and expects a reply of d5). The endgame tables also aren't as important as you might think at first. They only cover endgames without pawns, and so it is not that often that positions from these tables appear in a game. If one of these positions DOES show up in a game, and the computer misplays it without access to the tables, that isn't likely to give the human the win--it most likely will just let the human draw in a lost position. That's because the problem computers have with these endings without using tables is that they aren't able to see how to make progress from a won position so they end up hitting the 50 move draw rule. (Note that this only applies to games with a lot of pieces left. Even fairly old chess programs could do the basic piece-only endgames without needing tables). Thus, if the tables were taken away, the overall result would be that in the games where pawns remain (most games) computers would win a lot more than humans, and in games where all the pawns go away while there are still several pieces left humans would get some draws in lost positions. Overall, take away both opening book and endgame tables, and computers would still dominate, just not by quite as much because of the rare pieces only endgame that humans would sometimes draw from a lost position, and the rare case where the human could steer the opening into one of the few lines where book is still deeper than the computer can reach and that line's evaluation changes between the depth the computer reaches and the depth the book reaches.
- adamconroy 13y ago
  Table bases do include pawns. I don't think anyone would think humans are stronger than the best computers even if the computer didn't have opening books and table bases, I was just saying that to compare ratings isn't really fair.
prof_hobart 13y ago
I wouldn't say that was cheating. It's not like they've got the books sat in front of them. They are simply using one of the many advantages of being a modern computer - huge and fast memory capacity. But whilst the fact that computers are now better than humans at chess is interesting and impressive, it doesn't really matter in terms of things like the world championship. Machines can beat humans at all manner of competitive events - plenty of vehicles, and probably some robots, could go faster than Usain Bolt for example - but that's irrelevant when it comes to discussing the Olympics.

shaggyfrog 13y ago

This is not cheating in any real sense of that word. The computer has that opening book in its memory, so why shouldn't it make use of it any more than Carlsen is making use of his memory? What's the alternative? Harrison Bergeron-style handicapping of computers, to soothe our human egos?

tzs 13y ago

Today's computers would still dominate even if their opening books were taken away. Open book essentially represents a very extensive analysis of one position (the starting position) that has been carried out by humans over centuries. We aren't as fast as computers, but we've been working on this one problem longer and with massive parallelism, and so we've got the main lines covered quite deep. It used to be that most of book went deeper than a bookless computer could analyze in the time available for the opening in a timed game. This meant that a booked up human could steer the game into lines that appeared favorable for the computer when analyzed to the depth the computer could analyze, but were actually favorable to the human when analyzed to book depth. Computers are now fast enough that they can reach or surpass book depth in most lines, making it much much harder for a booked up human to steer the game into a favorable line. As an example of how fast computers are now, I just let Stockfish 4 64bit have a go at the start position on my 2008 Mac Pro (dual 2.8 GHz quad core Xeon processors, without hyper threading). I gave it 3 minutes (3 minutes per move is common in world class chess events). These were the settings: 8 threads, idle threads do not sleep, 8 GB hash table. It reached a depth of 30 ply (44 ply in selective search), and examined 940 million nodes, averaging around 5.3 million nodes per second. (It picked d4 as its move, and expects a reply of d5). The endgame tables also aren't as important as you might think at first. They only cover endgames without pawns, and so it is not that often that positions from these tables appear in a game. If one of these positions DOES show up in a game, and the computer misplays it without access to the tables, that isn't likely to give the human the win--it most likely will just let the human draw in a lost position. That's because the problem computers have with these endings without using tables is that they aren't able to see how to make progress from a won position so they end up hitting the 50 move draw rule. (Note that this only applies to games with a lot of pieces left. Even fairly old chess programs could do the basic piece-only endgames without needing tables). Thus, if the tables were taken away, the overall result would be that in the games where pawns remain (most games) computers would win a lot more than humans, and in games where all the pawns go away while there are still several pieces left humans would get some draws in lost positions. Overall, take away both opening book and endgame tables, and computers would still dominate, just not by quite as much because of the rare pieces only endgame that humans would sometimes draw from a lost position, and the rare case where the human could steer the opening into one of the few lines where book is still deeper than the computer can reach and that line's evaluation changes between the depth the computer reaches and the depth the book reaches.

adamconroy 13y ago
Table bases do include pawns. I don't think anyone would think humans are stronger than the best computers even if the computer didn't have opening books and table bases, I was just saying that to compare ratings isn't really fair.

prof_hobart 13y ago

I wouldn't say that was cheating. It's not like they've got the books sat in front of them. They are simply using one of the many advantages of being a modern computer - huge and fast memory capacity. But whilst the fact that computers are now better than humans at chess is interesting and impressive, it doesn't really matter in terms of things like the world championship. Machines can beat humans at all manner of competitive events - plenty of vehicles, and probably some robots, could go faster than Usain Bolt for example - but that's irrelevant when it comes to discussing the Olympics.