Sudoku. Tutorial #7 Tricky

hi everyone this is Robin the Sudoku guy with session number seven and uh it's my privilege this time to do a puzzle with you that is a little bit more challenging and uh but if we should be able to do it but there's lots of little techniques and clues that I'd like to give you as we go along our way let's assume that you look at this and you don't see something that's outstanding a picture in the eye and we'll start off with a normal procedure starting with the um one's up on top on the horizontal blocks there's nothing two there's nothing three there's nothing four well no nothing but not till we get to five that we see something here we have a five in the middle a five in the top so let's look at this here we can put a five there and a five there sixes there's no sixes sevens Seven's too many too many cells eights we have two eights we have a bottom and a top so there and eight could go there or there but I can't put one there because there's an eight down in here nons well we have a bottom here and a top so in that case we could put a 9 here and a 9 there that's it now let's do the middle set of blocks in here horizontal ones oh it can go many places leave it twos twos have got a bottom and a middle we can put a two here and a two there threes we have two threes at top and the middle over here we would have could have a three in the bottom but there's a three down here so that cancels that cell so this is where the three goes now let's look at the ramifications we have a center a left here it's going to be on the right so we can eliminate that eight and it becomes a three now because eight could only fit in two cells up in here in this block we can now put that as a big eight so here we go now let's look at the ramifications of this three here uh top bottom middle we've got a three here so the three has to be over there so we'll put a three over there watch the ramification of that we have a right we have a left it has to be in the middle in the center down in here it can be in those two cells but we come across here there's a three so it has to be there was the ramification of that we have now have a bottom we now have a middle but in the middle block we need a top it can be there or there but it cannot be there because there's a three there so it has to go there wow now let's go um are there any can we go any further than that we've got you know what I think we have got all the threes we've gone right around the whole puzzle and got all the threes just because we notice that a top and middle in there now we'll go to Fours I can see um here um we could use the cross but it still leaves us with too many cells let's go to five five we got middle bottom two fives over here but two little ones so we'll put the two little fives in there okay now let's go to six there's only one six but in this block here this six eliminates six as being in here and there's only two cells left because there's only two cells I'm going to put a little six in there in there we'll see what happens down the road sevens well now this is interesting we can use the cross technique here if I take this 7 and go up and that's 7 and go across the only cell left in this block by doing that is there and again if you have trouble seeing that some people visually have trouble with that you're welcome to get a piece of paper and put it across or a pencil and put them across and see what happens that way now because we had that seven what are the ramifications well we have to go up and across let's go up first Center left right we could have a little seven there and a little seven there let's go now across we have a top a middle this becomes a seven any ramifications of that yes there is we have a Setter a left here we can have one there all there so we can put two little sevens over here see what we did just because we saw the opportunity to use the cross technique now when I did that I've noticed that this particular row has only got two left and if I remember if I look at this carefully let me think now there's a six nine left in here check me out and some people say oh you're going too fast Robin I can't keep up well if that's the case my suggestion is stop the tape go back and we'll look at it again or or stop the tape and think work it out yourself see how I got that answer in this case there's two cells left it's a six and a nine because it's a six and a nine and because we have a nine up there this becomes the sixth and this becomes the non therefore this can be erased and we're left with a full row completed now what's the ramification of this nine that we just put in and what is there any ramification for the sex let's do the nine first because I can see something here that 9 eliminates this nine therefore this nine becomes a real nine so we can put that in and now we have a left we have a center and down in this block we have a nine nine that can go there so we can put it in I'm looking right and I'm looking left and I don't see any other nine so it's going to be a little nine so now what about the six any ramifications of that six yes I could say now that we have a center we have a middle we have a top and over here we could have two little sixes uh so let's put those in we know that that's the only two places in this block a six can go and that's going to help us down the road um we've done we've now gone up to no we were up to what number here doing the center here we did fours we did the fives we did the sixes we did the sevens now it's turned for the eights well we can have an eight wow we could have an oh this is something I've just noticed and we probably missed this out before actually I knew it but I forgot to point it out but here's a good example of where you could see something if you there's something there that you missed further on using these techniques that I show you and this procedures that I show you you'll be able to pick up what you missed we have an eight a bottom a middle it has to be on the top it could be there or there but this eight means it can't be there it has to be there did you see that opportunity earlier when I put the eight up there yes I miss I did the threes when I forgot the eights okay let's um it's good this is very good for the memory you've got to remember the procedures and remember all little techniques to use fine and now in this block because we put that eight in we're left with a one and a nine let's put them in one and a nine and a one and nine matching pair okay boys we're making some progress here um we did the Apes and now we we've got the nines um I'll have to leave it at that I think now let's go to this set of blocks once I don't know about you but I have just noticed that using the the tip cross Technique we can actually get some people call this dicing whichever system you want to you want whatever you want to call it just know the system of the technique here is a one you go across there that eliminates any one here this one eliminates that one and that one and that one so that's the only place a one can go so we'll put that one in and see what ramifications we can get well I can tell you right now looking up one one one this now becomes a one I'm looking at the puzzle very on an angle here so I hope I see it all and therefore because we knew that only five could go only in two spots this now becomes a five good now any ramifications of that five well we've got all the fives up here now down here there's several places we'll leave it for the time then um we were up to we did the ones all because of the ones twos there's no twos along here oh there's a possibility of I didn't go across this way one here one here we could have a one there or we could have a one there twos there are no twos leaving threes the threes are already done fours well here's an interesting we got a top and a bottom so the four can go either there or there let's look up any fours no but I see something and here's a situation where you may not have seen it but later on it will be discovered so sometimes yes you do miss something but later on you'll Discover it I'll point it out when I get to it because I can see it coming ahead um fours fives there's no fives along the bottom well sixes well a six could go because of that six the six could go all over the place there and there and there and there I'll have to leave that I think and it'll come later I can tell you that because I can see what's going to happen down the road um six sevens no sense eight wow look at this eight we have a middle we have a top so therefore it has to be in the bottom here there's an eight already here so this becomes an eight now you probably wondered why I paused a little while ago I was looking at eights but now I see where what happened that's good um nines any nines along here no they're not so we have to now do the vertical blocks once not much luck there twos twos could be here we could either have a two here or a two down in here uh threes well we've done them already earlier fours now here's a discovery because we have a line here completely filled this is a vertical line in this block if we had a four if we use if this became before we would go left center right but we can't that's filled up so that means that this four will not work we can erase it and therefore this one it's only left the one that's left becomes your four and that's the thing that I noticed before and when we were doing the crosses blocks across here but we found it now now what's the ramification of that four we have a right we have a center and over here we'll have a four over there or there very good science we have two fives a right and the left it has to be there or there let's put them in okay um sixes sixes whew not a lot of luck there because there's all kinds of places it can go um sevens now this is something that is really neat to know it's another technique when you look at this seven there's only the one seven but if I look up to the up instead of down but I look up I notice that a seven cannot go there because of that it's in that same column the seven has to go there or there because of that seven so let's put those in and that's going to help us because now we know the sevens in this block are going to be on your left that's in the center the seven has to go down there or there but it cannot go there because there's a seven there so it goes down in here so because of that little technique we've got a new number now let's look up we've got the sevens up in there but let's look across this way as a result we've got that seven bottom top has to be in the middle it can't be there because of that seven therefore it be this becomes the seven and all because we noticed this phenomenon here this little technique we've got two more sevens eights well the eights are already done nines well they could go then and then they could do in several spots I think we'll just leave that now let's go to the middle set of vertical blocks once all right too many cells empty twos gosh I don't see any twos threes they're all there fours well here's an interesting situation here's a four which eliminates of being a four in any of these here but it has to be there or there there's no fours along here so we can put in a 2 4 here or and a four there if there is going to be a right and if these are in the center over here we have to have a four and there's one space left for it so we can put it in which means we can cancel this four therefore pun this becomes the real four now let's see if that has any ramifications four four four four four four four four yeah we've got all those fours in those blocks already that was that was helpful um moving right along we did the fours what about the fives we have two fives we have a left and we have a right a five has to go there there's no arrows for it to go which is going to be handy five very good now uh let's go to the sixes well we have sixes could be there there there there all kinds of places I just noticed something it's talking about sixes that it was doing a cross here down here you can't have a six cross there you can't do a six therefore that is eliminated this one is eliminated this becomes a six and therefore this becomes a 9 if that becomes a nine what does this become a two one two yes a two now what are the ramifications of all that one well first of all we finished this whole block um which I missed before but we caught it again um secondly that eliminates this too and this two therefore becomes a real two because we we worked out the two could only go in those two spots so this is a two if that is a two we have a middle and a bottom and a top we can go over there and do that too if that is a two a right a center a two has to go there if that is a two are there any other ramifications well I can see all kinds of things as a result of that procedure um let's let's see what happens because of this two we've only got one left in there and let's see what number it is one two three four five it's a six which is great because that cancels out this six therefore this becomes the six and we can check it out by going Center left right well that that was helpful um we can I'm looking at other things that have come up as a result of that little procedure that we did with the two well this block here has only got two left in it it is a let me see it's a five and a nine a five and a nine well there's a five already there so this becomes a nine you see I took a shortcut there I hope you could see what I was doing and this therefore becomes the five if let's look at the ramifications of that one here's the nine there's a nine so we know we have to have a nine over here or a here uh but this five cancels out that five um so we can make this a real five and that works right center left and now we're left with only two numbers in here and what numbers are missing let's have a look we're missing a four four one two three four uh five six seven eight four and a nine so let's put the four and a nine in four and a nine what are the ramifications there well we'll have to see four and a nine see anything right now let's push on here we were doing the verticals in here and we've now done gone through all the vertical blocks here we got up to five six six or we could do a six six this becomes a six and because that becomes a sick we can work out what this is let's have a look it's a one one two yes it's a one what does that do that makes it well this is unbelievable the ramifications of all this this becomes a nine and this becomes a one oh that was neat uh if that's a one one one this becomes a one now because we had this five down here we looked up this way now we're going to look this way we should have make this into a five because we have a bottom a middle it has to be on the top which cancels out this far down in here wow and we've only got one left in this block and I think it's a one two three four five one two three it's a six I believe yes it's a six if that's a six we have a center we have a right one of these is a six and it has to be this one here because we have a six six six therefore if that's a six this becomes the seven because it's the only one left so we can eliminate this seven what does that mean that's seven that means that this becomes a seven and now we're really we've finished up another row way to go and in this particular look there's so much is happening here um in this particular uh row up here we've got only two left and you could probably work out I think it's one of them is going to be a one because we've got a middle and a bottom one of them has to be a one and the other one what do we see now one two and one of them has to be a two there's a two down here so we have a one two up in here let's see this see what happens now let's look at something else here we have oh because of this nine this becomes a four and this becomes erases my pins nothing to run out of it gets true to the end of the puzzle that becomes a nine if that becomes a four what does this become let's have it check it out and see what it happens it's a one yeah it's a one on this row so we make that into a one and that fits because we can double check it by going top bottom middle if that is a one what are the ramifications of this this becomes a two and that becomes a one so that becomes a two oh you've got it and that becomes a one if that is a 2 then this becomes a four because there's a four already down in here so if this becomes a four check it right center left here we have a two we have a left right center so this has to be the two and I think we're almost there there's only one left down in here one two three four five six seven eight it's a nine and we're going to check that by going up and down here we could have checked it by going that way it could be checked it within the block but we have finished a more complicated puzzle I hope you got a few little pointers of this session bye for now foreign

Channel: Sudoku Guy

Views: 67,863

Keywords: how to solve sudoku, sudoku lessons, sudoku for all levels, sudoku for beginners, instructions on how to solve sudoku, demonstrations of sudoku solving. brain fitness, memory practise, sudoku for seniors, sudoku for the frustrated, advanced sudoku strategies, spare time activity, fun with sudoku, simple sudoku, sudoku solving tricks, sudoku for dummies, sudoku tutorials, sudoku, learn sudoku solving.

Id: y7abBpSwUDA

Length: 22min 40sec (1360 seconds)

Published: Mon Sep 21 2015