I'm showing you some tips and techniques in solving Soduku puzzles. The next one is a master strategy called X wing. Here's an example of an X wing here of a possible solution. We're looking at candidates here. This is where 6 can be in this area here. These are the only ones where 6 could be. Basically when you're looking at this, you think in your mind. Okay, if 6 were here, this would have to be a 4, that would have to be a 6, and that would have to be a 9, which means that in this case here, whatever this number is will be the same here. Same if you think a 6 is here. If a 6 is here, that would make this a 9, that would make that 6. Because of the only two possibilities of this row here, it has to be a 6 here because it can't be up there. There's where it gets it's name from. Just logically deducing that. Again, this is not something that will give you a thing right away, but in this particular example it does because you know that if a 6 is here, this has to be the same. If this is a 6 and this is a 4, then this has to be a 6 because this can't be a 4. So these values are going to be the same. That means if this is a 6, this one here. If this is a 6, this has to be a 6 as well using the same thing as we did before. So making the X with this one here, will be the same as here. So 6 has to be here or here, which means that you can move the 6 of this particular one. So this particular example, it got us a value up here. Again, spotting these you'd be looking at something that's equal to this rectangle here and they're only where the 6 could be. That's how you would spot that. In this particular example, this happen to give you a move ahead or it may not. This is where the 6 will have to be in this row so you'll be able to eliminate it from other parts of the puzzle. In our next clip, we'll show you another master called sword fish.