Judan

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Location: Cambridge, UK

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Rank: UK 4 dan

KGS: Uberdude 4d

OGS: Uberdude 7d





For the first game I chose Master game 2 vs Zhang Zilang 2p (weak pro goratings #557), as it's fairly calm opening with Master's distinctive shoulder hits, and both Redmond and dhu reviewed it so I can compare with those. Full game at



Click Here To Show Diagram Code [go]$$B Zhang Zilang 2p (black) vs AlphaGo Master

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AG gives black a 46-47 win % on the empty board with 7.5 komi, and Zhang starts with the best of 4-4 at 47.1% (it's not clear what the error is in these figures, I think about half a % given the fluctuations of subsequent moves, also AG may choose to play a move within about 1% of the best number). White 2 is shown as black down to 46.6%, but that position can't be worse for black than what AG expects when black played move 1, so there's some fluctuation/error. dhu noted Master as white doesn't seem to fear allowing diagonal opening, but for move 3 AG says the digonal 4-4 is best at 47.0 whilst the 3-4 played is 46.6! (though unclear how significant that is). Black 5 makes small shimari, big one (high or low about 1% better). In the real game Master played 6 as small low (45.4), but teaching tool shows small high a little better (44.7), we often saw it play this when black played 5 as the big low shimari. There was a consistent lesson from AlphaGo in those games and this tool that white can afford to make a shimari for move 6 in these sort of orthodox openings rather than splitting or approaching on the top side. In this case the k17 split is 47.8, 3.1% worse than e4, quite a significant mistake! o17 approach is 46.0, just -1.3. So the modern style of approach being better than split does seem to be correct, but we just didn't realise a shimari was even better!



Click Here To Show Diagram Code [go]$$Bcm7 Game

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AG approves of black 7 modern style shimari from 4-4 (lower right 3-3 invasion just 0.1% better) and then makes its own for 8 too. At this point k17 split is 2.1 worse, splits really suck according to AG, it seems corners are gold and sides are mud not silver. Black 9 then takes the middle side point, a good double purpose move in classic opening theory, but AG says q7 shoulder hit 1% better. Master made shoulder hit on left, but AG teaching tool says the other shoulder hit was 0.5% better, this is presumably the high temperature parameter during these games to increase variety (or did Aja have a readout of multiple moves and sometimes chose the non-top one?). Zhang blocked on the 4th line (in Master game 15 Park Junghwan blocked on the 3rd line), however AG says the best move is this tenuki to split left side and the following shoulder-hit obsessed continuation is expected!



Click Here To Show Diagram Code [go]$$Bm11 AGT recommendation

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After all the ignored should hits note 21 extension allowing hane at head of 2, and that it views 22 as sente for top side (what was follow-up if ignored, q17?) which allows the double hane to make a nice encircling for white.

Click Here To Show Diagram Code [go]$$Bm21 AGT variation

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Anyway, black didn't realise the correct response to a shoulder hit in the opening was tenuki, so white then jumped despite the AG teach saying q13 shoulder hit immediately .4% better: this is not so significant plus when there are two important sente points AG seems to like flitting between them. Interesting though it says that (as after the initial shoulder hit) after both f14 jump or q13 shoulder hit instead black should play the d9 split (a), it really is the key point of this opening. Instead black played 13 to split the lower side (normal said Redmond, or "locally it's a good move", no comment on globally) but this was 41.0, -2.3 on d9. I think we can see a similarity here to AG's unfavourable view of k17 (either for black or white), both moves are splitting a side with strong groups of the same colour in both corners, so to build or split in such an area is playing (relatively in terms of the whole board) close to thickness, the corner groups are untroubled by such a move so it's easy to tenuki and play in more open areas of the board. Also the d9 split AG recommends has some attacking effect against the top left shoulder hit group, splitting it from the lower left. White played checking extension from the right (dhu expected from left, AG teach and Redmond no comment, my answer is black AG would not play so simply as o3 allowing kick) and black made a standard 2 space extension to make a base, giving white sente to make another shoulder hit.

Click Here To Show Diagram Code [go]$$Wcm12 Game

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There's several interesting aspects in this short exchange. The 2-space extension to make a base is a very standard idea and elicited no comment from Redmond, but AG thinks it is slack and instead wants to (yes, you've guess it!) shoulder hit the shimari, then bully it into overconcentration from the other side and tenuki. I remember in the 1st AG vs Ke Jie game Bill talked about how making 2-space extensions for a base was an ancient idea but maybe we could be wrong about its importance too often.

Click Here To Show Diagram Code [go]$$Bm15 AGT's recommendation

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$$ | . 6 O , 2 1 . . . , . . . . . O . . . |

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Another interesting detail is that AG actually prefers (by 1%) to shoulder hit the top right one move earlier (14 instead of 16), before the checking extension. At this point it expect black to block at q14 and then it would play n3 as before. I think this is not just AG MCTS random flitting, but a probe: if black answers the should hit with r13 or s12 (which is the move it recommends when it was played in the game) to place more emphasis on destroying white potential on the right side (and less thickness for top side and pressure on the shoulder hit) then it would no longer play the checking extension from the right side but from left or tenuki.



Click Here To Show Diagram Code [go]$$Bcm17 Game

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Black also blocks the 2nd shoulder hit, AG says slide to s12 0.4% better and then white would d10 extension on left. By the time white jumps for move 18 black is already down to 38%, a 10% loss! Zhang played the solid extension to p14, Redmond explained how he prefers not to wedge because it makes white stronger (if white answered extend at a black prefers not to make b-c exchange). However, I thought this was slow, and Redmond also preferred tenuki to reinforce the lower group at d. AG doesn't mention this move but recommends d10 instead, a full 3.4% better than the game move, a big mistake. It also shows an interesting continuation with black using the o3 attachment to make some extra eyes for the 2-space extension group, and then white using a tesuji to chop it off again at the expense of sacrificing a stone (as this is a AG self-play black stays around 39% win):

Click Here To Show Diagram Code [go]$$Bcm19 AGT recommendation for black 19

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$$ | . . . . . . . . . . . . 5 9 7 0 . . . |

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Click Here To Show Diagram Code [go]$$Bcm29 AGT continuation

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$$ | . . O , . . . . . 7 . . O O . O . . . |

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$$ | . . . . . . . . . 5 . 8 X X X O . . . |

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$$ +---------------------------------------+[/go]



The game continued as below, with Master playing another shoulder hit (fairly normal human one though) to press on the lower black group. AG actually shows an invasion at n17 to be a little better, but this leads to some crazy variations I don't understand and isn't in the theme of the actual game. Black blocked, and then wedged, both very normal moves, but AG thinks both are too simple and wants to use the thinness of the lower right corner to achieve a more efficient result (in Zhang's defence he probably didn't know he was playing AlphaGo in this early game so could just be playing ok simple moves which can beat most Tygem 9ds, if he knew he was playing AG maybe he would have searched harder for these more subtle and refined moves, but still tough in 30 seconds).

Click Here To Show Diagram Code [go]$$Bm17

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$$ | . . O , . . . . 4 7 6 . . . . O . . . |

$$ | . . . . O . . X 5 9 X . O . . . . . . |

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$$ +---------------------------------------+[/go]



Here's AG's recommend first dodge. It must think diving into the corner at p2 is sente (thought I'd like to see what happens if white ignores and played j3 seeing as black ignored that shoulder hit) and then pushes up. White then tenukis to its n17 invasion obsession and black spends a thick move at j5.

Click Here To Show Diagram Code [go]$$Bm17

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$$ +---------------------------------------+[/go]

So we don't actually get so see how p2 helps black if white continues, here's my first idea (if white will obediently answer o2 at q2):

Click Here To Show Diagram Code [go]$$Wcm24

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$$ | . . O , . . . X O , 1 5 . . . O . . . |

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$$ | . . . . . . . . . . . . 6 2 X 3 . . . |

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$$ +---------------------------------------+[/go]



AG's variation for black's wedge though is very elegant, and 5% better! Loses something in the corner but breaks white's centre seal.

Click Here To Show Diagram Code [go]$$Bm23

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After the wedge the game continued with Master's solid connection, perhaps a bit unusual locally (m4 normal) as it gives black m3 in sente, but reduces the power of j4 cut. Black is now at 30%, and then pushes through where white ignored before, but this drops the win% to 27% on move 29, what a quick collapse!

Click Here To Show Diagram Code [go]$$Wm26

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$$ +---------------------------------------+[/go] I thought I would resurrect this thread, now that DeepMind have released AlphaGo's evaluations of the opening of the Master series of games as part of the AlphaGo teach opening book . Michael Redmond reviewed quite a few of these games, and would often make comments like "I wish we knew what AlphaGo would do" or wondered how the human ended up looking behind already by move 30. We can't ask AlphaGo what it thinks of arbitrary moves, but we do have its "win %" metric ( viewtopic.php?f=18&t=15312 for discussion of what exactly this is) for each move played in the game (up to move 30ish) plus the move it would play. Note that once we get into deeper positions AlphaGo Teach usually only gives us the game move and AG's preferred one, and the coloured circle legend on the website of "Green = move AG would play; Purple = move human would play" seems inaccurate: for these games purple means move human or alphago played in the actual game, whilst green is suggested variation from AlphaGo. Also we don't know how close in win % other moves not shown are to the one they chose to show us, they could be very close or far worse.For the first game I chose Master game 2 vs Zhang Zilang 2p (weak pro goratings #557), as it's fairly calm opening with Master's distinctive shoulder hits, and both Redmond and dhu reviewed it so I can compare with those. Full game at http://www.alphago-games.com/view/event ... /1/move/50 . Redmond's review at https://youtu.be/LJ8d_KTKZ-Q AG gives black a 46-47 win % on the empty board with 7.5 komi, and Zhang starts with the best of 4-4 at 47.1% (it's not clear what the error is in these figures, I think about half a % given the fluctuations of subsequent moves, also AG may choose to play a move within about 1% of the best number). White 2 is shown as black down to 46.6%, but that position can't be worse for black than what AG expects when black played move 1, so there's some fluctuation/error. dhu noted Master as white doesn't seem to fear allowing diagonal opening, but for move 3 AG says the digonal 4-4 is best at 47.0 whilst the 3-4 played is 46.6! (though unclear how significant that is). Black 5 makes small shimari, big one (high or low about 1% better). In the real game Master played 6 as small low (45.4), but teaching tool shows small high a little better (44.7), we often saw it play this when black played 5 as the big low shimari. There was a consistent lesson from AlphaGo in those games and this tool that white can afford to make a shimari for move 6 in these sort of orthodox openings rather than splitting or approaching on the top side. In this case the k17 split is 47.8, 3.1% worse than e4, quite a significant mistake! o17 approach is 46.0, just -1.3. So the modern style of approach being better than split does seem to be correct, but we just didn't realise a shimari was even better!AG approves of black 7 modern style shimari from 4-4 (lower right 3-3 invasion just 0.1% better) and then makes its own for 8 too. At this point k17 split is 2.1 worse, splits really suck according to AG, it seems corners are gold and sides are mud not silver. Black 9 then takes the middle side point, a good double purpose move in classic opening theory, but AG says q7 shoulder hit 1% better. Master made shoulder hit on left, but AG teaching tool says the other shoulder hit was 0.5% better, this is presumably the high temperature parameter during these games to increase variety (or did Aja have a readout of multiple moves and sometimes chose the non-top one?). Zhang blocked on the 4th line (in Master game 15 Park Junghwan blocked on the 3rd line), however AG says the best move is this tenuki to split left side and the following shoulder-hit obsessed continuation is expected!After all the ignored should hits note 21 extension allowing hane at head of 2, and that it views 22 as sente for top side (what was follow-up if ignored, q17?) which allows the double hane to make a nice encircling for white.Anyway, black didn't realise the correct response to a shoulder hit in the opening was tenuki, so white then jumped despite the AG teach saying q13 shoulder hit immediately .4% better: this is not so significant plus when there are two important sente points AG seems to like flitting between them. Interesting though it says that (as after the initial shoulder hit) after both f14 jump or q13 shoulder hit instead black should play the d9 split (a), it really is the key point of this opening. Instead black played 13 to split the lower side (normal said Redmond, or "locally it's a good move", no comment on globally) but this was 41.0, -2.3 on d9. I think we can see a similarity here to AG's unfavourable view of k17 (either for black or white), both moves are splitting a side with strong groups of the same colour in both corners, so to build or split in such an area is playing (relatively in terms of the whole board) close to thickness, the corner groups are untroubled by such a move so it's easy to tenuki and play in more open areas of the board. Also the d9 split AG recommends has some attacking effect against the top left shoulder hit group, splitting it from the lower left. White played checking extension from the right (dhu expected from left, AG teach and Redmond no comment, my answer is black AG would not play so simply as o3 allowing kick) and black made a standard 2 space extension to make a base, giving white sente to make another shoulder hit.There's several interesting aspects in this short exchange. The 2-space extension to make a base is a very standard idea and elicited no comment from Redmond, but AG thinks it is slack and instead wants to (yes, you've guess it!) shoulder hit the shimari, then bully it into overconcentration from the other side and tenuki. I remember in the 1st AG vs Ke Jie game Bill talked about how making 2-space extensions for a base was an ancient idea but maybe we could be wrong about its importance too often.Another interesting detail is that AG actually prefers (by 1%) to shoulder hit the top right one move earlier (14 instead of 16), before the checking extension. At this point it expect black to block at q14 and then it would play n3 as before. I think this is not just AG MCTS random flitting, but a probe: if black answers the should hit with r13 or s12 (which is the move it recommends when it was played in the game) to place more emphasis on destroying white potential on the right side (and less thickness for top side and pressure on the shoulder hit) then it would no longer play the checking extension from the right side but from left or tenuki.Black also blocks the 2nd shoulder hit, AG says slide to s12 0.4% better and then white would d10 extension on left. By the time white jumps for move 18 black is already down to 38%, a 10% loss! Zhang played the solid extension to p14, Redmond explained how he prefers not to wedge because it makes white stronger (if white answered extend at a black prefers not to make b-c exchange). However, I thought this was slow, and Redmond also preferred tenuki to reinforce the lower group at d. AG doesn't mention this move but recommends d10 instead, a full 3.4% better than the game move, a big mistake. It also shows an interesting continuation with black using the o3 attachment to make some extra eyes for the 2-space extension group, and then white using a tesuji to chop it off again at the expense of sacrificing a stone (as this is a AG self-play black stays around 39% win):The game continued as below, with Master playing another shoulder hit (fairly normal human one though) to press on the lower black group. AG actually shows an invasion at n17 to be a little better, but this leads to some crazy variations I don't understand and isn't in the theme of the actual game. Black blocked, and then wedged, both very normal moves, but AG thinks both are too simple and wants to use the thinness of the lower right corner to achieve a more efficient result (in Zhang's defence he probably didn't know he was playing AlphaGo in this early game so could just be playing ok simple moves which can beat most Tygem 9ds, if he knew he was playing AG maybe he would have searched harder for these more subtle and refined moves, but still tough in 30 seconds).Here's AG's recommend first dodge. It must think diving into the corner at p2 is sente (thought I'd like to see what happens if white ignores and played j3 seeing as black ignored that shoulder hit) and then pushes up. White then tenukis to its n17 invasion obsession and black spends a thick move at j5.So we don't actually get so see how p2 helps black if white continues, here's my first idea (if white will obediently answer o2 at q2):AG's variation for black's wedge though is very elegant, and 5% better! Loses something in the corner but breaks white's centre seal.After the wedge the game continued with Master's solid connection, perhaps a bit unusual locally (m4 normal) as it gives black m3 in sente, but reduces the power of j4 cut. Black is now at 30%, and then pushes through where white ignored before, but this drops the win% to 27% on move 29, what a quick collapse!

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