Match 4 15 Minute Summary - Google DeepMind Challenge Match 2016

Key Takeaways

[Music] hello and welcome to the game highlights for game four in the Google deepmind challenge today Lee sadol was looking for the weakness in alphago which he had not been able to find in the first three games today he found it Michael show us how yeah well well so we begin with the game absolutely yes start point Alpha go is black yes at this point it's exactly the same opening as it played um in the second game and at this point lisad all change tactics in the F in the second game he played here and alfago actually left that so this was actually a kind of a surprise because just about everyone was expecting alphao to be sort of orthodox in his opening and so when uh in that game alphao left it and played on the on this side here uh so leis apparently didn't like that and so he changed his move here um top players also people tend to like to um change their moves um just to avoid the same game for one thing okay um and maybe he thought that it was important for him to keep uh Al Alpha going the defensive a little bit because this sort of threatens to attack these Stones so so black is sort of needs to play that extension um and gives leisle the chance to play the kakari very common position here um locally there's a lot of moves that white can choose from um basically um any move uh directly protecting this one stone will allow black to play towards the right side here and make a framework here while letting White live that would be also a josei but um since black does have this weak Stone here it sort of makes sense for white to switch the side here and allow black to take the corner and create a white uh weak black rout and now black played once here this is really big in helping Black's framework and white played the final you could call that the final big point or final Oba then what uh this is an interesting move interesting move it's not unheard of it's a move that have has been played before and there after if White had played here black would have been satisfied to play forcing moves from outside sort of forcing white to put put a lot of stones in that corner so this was the plan so white says no you can't do that now Black's aim is to try to get some Maji in the corner like there's moves like this which can cause some trouble in the corner but it's interesting that before black does that Alpha go plays once here in an attempt to sort of erase the side first and then go back there later and I don't really know why I I think leedle might have been worried that at this um at this point in time now alfago would be trying something in the corner I'm not really clear as to how that would turn out but um normally I think white should have been playing one push at least and hopefully if black plays here then it would be a different story when might plays here there would be more more space for this white sure and actual game white played here medely and this does sort of make white a bit cramped so this is something that I didn't really like for white and I thought it was a bit difficult in this fight uh both the black group and the white group are actually weak groups and if you look at the positions on the side we can see that it looks like for instance if white plays here if we just look at this position Black's group is the weaker one but there's the fact that now it's Black's move so black gets to K say play the the key move here mhm that's a kind of a vital point in white shape and so because of that the strength of the two groups is maybe about the same there's also the fact that if black can curl around on the top here there's going to be a big moyo in this area Okay so white decided to play the safe move we can see alpago playing very aggressively here pushing and just closing off the center um and then connecting this is sort of a vital point in white shape with this move white has a living shape and so far white has taken territory here here here and a framework here which is not really so big uh black this is not really territory black has territory in the corner maybe here and then this framework so what happens to this framework is really important in this game it's white turn white plate here and so white started by invading the side here but decided that it was a bit heavy to actually be moving out with these Stones so he played a very light move here this is sort of moving out not really trying to save all of the stones but also looking at the cut here and this cut came later in the game but this is always something that white is sort of hoping to play at some point okay back this is similar uh to the magic move in game two although that of course was this is more of a normal shoulder hit right it's a more normal should shoulder hit in this case actually black is trying to sort of cover up on the top and Surround these Stones depending on how white handles it so in that way it's it also resembles a move that Leed played in game number three in which case he was attaching against a white structure um in the lower right actually um in an attempt to attack White Center group so it's a this is basically an attack uh a bleak attack against white stones here and instead of trying to take territory over the side which would sort sort of um fall into Black's trap white does have to push through here and try to make a connection with these two GRS again just like here alphao is playing very strongly it's quite a similar shape actually um at this point white does have a kind of a connection if White had for instance played something like this yeah this it would have been much more peaceful black would probably just take the one stone and black would have some thickness towards here would still have the torner territory and this territory and would later have a move here to cut this off so why would need to put one more Stone in for instance here um and this the kind of clumsy shape here is what Le all didn't like I see because he also has a weak point here so the whole group here um although it's connected and saved now it's still not a very happy shape so and and the fact that black is thick here means that Black's going to get some extra points in the center right so that's why Le said just didn't like that I suppose okay and since the ladder is good for white so he escaped here the drawback is that this move is attacking white here it turns into a kind of a trade now at this point you were feeling pretty good for Alo for alphago right um I think alphago should have a lead at this point um and it all depends on how how much white can get out of the AI here because there's a lot of AI or potential especially for this Stone and this Stone and the weakness in the cut and the Honea here I'm just putting a lot of stones down this this really puts these stones into so there's a lot of U there's a little bit of potential here um and even professionals when playing will not be really sure whether this stone is completely dead or not okay but for the time being uh covering hair is a very strong move for black white can't really allow that to happen so white had to put put a stone in here black plate here this is a large scale now if this move happened to be it turned out that white managed to destroy this black center territory with a brilliant sequence um and if that is true if that um if that worked actually maybe black should have been a bit more cautious here this would be maybe a bit over cautious but at least something like this to avoid that kind of thing I see but um my um Theory here is that the moves that Lee SLE did to break up this Center they took me by surprise I wouldn't be surprised if they were sort of outside the um the tree of uh variations that alphago was creating because it was a brilliant sequence which is really amazing though because and we'll see this shortly but I mean alphago performed virtually flawlessly in the first three games yes and in this game also I think alfago is playing a good game okay yes okay so suddenly well the moment leas at all sort of um it's a pretty standard move noral special this is another well there's a choice here between this move and this move um they both have their drawbacks um the whole place the situation here this black group has some Dum as Murray a lack of Liberties there's weak point and black all over the place so it is a kind of a worrying situation however black place um black this looked like it was a safe move to me when when Black played it MH and black white Cuts here again uh playing Atari and allowing white to get some Stones lined up here would set up this move right and that would be a disaster collapses coming this side would allow this to be sente and white would be again would be able to use this kind of AI to run out with a fairly good shape and that would put these stones in trouble so this is the move that comes to mind a ni now white plays here and this is this is forcing white black has to answer this and in order to make this cut work white really needs he needs this move this is a forcing move that obviously will work it white Black's going to answer it white needs this forcing move um and it still doesn't work because white Cuts black comes out here and black can come here to capture the two stones right so white needs one more forcing move here right now if we do this in order it's just not going to work um because uh white black can answer the final forcing move with this um this move right and um white cannot get out here just doesn't work um so the move that lisad all played was just brilliant and it was um he wouldn't have been playing this way to start with if he hadn't uh been sort of feeling the potential for this move already I don't know if he had it completely read out or maybe just was sort of smelling something that happened um and he he he was very modest about it in thepress the press conference but um all of this stuff he's doing would be sort of meaningless if he hadn't had something like this in mind when he did this was a brilliant move I think it got a wow out of me while I was doing the commentary did um basically it's as if black plays here um it means that white will get that extra forcing move here um and this would set up the capture here of the two black Stones not really paying very much for it capturing these two stones would give white a victory um in actuality black plate here um white push through here black covered and white cut now at this point it's still not clear what's going to happen if black takes the one stone white can force with this and force with this and again White's got the three forcing moves that he needed so white can cut here uh and capture the two STS right so it's these three points that white needs to make this cut work so that's that's relatively simple um in the actual game Alpha goes stop playing in this vinity at this point now the move that I was looking at was this one and if white plays here it's not going to work uh because white cannot capture this Stone in the ladder so this looks bad for white but there is potential on this side for instance if white plays here and black plays here white can push through here black covers white cuts and now white plays here after this the throw in here which kills these stones and the cut there well this is bad too yeah so this would capture these Stones here very nice so this would be a disaster um I'm not really clear what happens if black plays this move on this side in which case it doesn't really seem to work um but in act the alphao Apparently decided that didn't work to to play here and so alphao started doing stuff like this which is and just didn't work just doesn't work right after this actually the game sort of deteriorated for alphago because alphago was just doing all sorts of things that did not work and now took here now took yeah right and and then played down here and white just took black played the key point but black was already losing the semii here this whole sequence it didn't um black gained some back on here but it increased White's territory here really wasted the black potential there and in the center again this point and cutting off the two stones is Mii so at this point the game is already looking good for white it's an amazing turnaround for lead all who had you know basically we we had counted we counted you know 80 8 90 100 points without anything like this the game would have been hopeless for white and this was really a brilliant move that was led up to by a sequence here in which at least was certainly um sensing something there in the middle of Black's territory well thank you for it was it was a long seemed like a really long commentary again another long complicated game uh thanks for leading us through it uh congratulations to leis sadal for finally finding uh a weakness uh in a program that up until now has been seemed Invincible but it's got a bit of a bit of a flaw so uh we will look forward forward to game five uh the final game uh with great anticipation uh thank you again Michael thank you [Music]