Exploring the Cozio Defence


Hello chess adventurers:

As you may have surmised from the title, I am exploring the merits - and potential pitfalls I guess as well - of the Cozio Defence to the Ruy Lopez.

It is one of chess' last final frontiers or mysteries from an experiential viewpoint, from what I gathered so far. As such, it is even more exciting to know that less theoretical work has been done on the Cozio defence than almost any other chess opening, and it is thus worth exploring in depth! For in it there may be yet some brilliancies to find...

... Not that I might author these - I wish! - but perhaps, en masse we could deduce but one or two nice gems by active pursuit.

So I am going to post recent and/or interesting Cozio Defence games as I find them or play them, and I invite all other relevant contributions and ideas/analysis/feedback.

Try this defence out, and let's see what happens - post it here! Then we can share in the colective, and stronger knowledge attained in collecting data as such.

Here's my first contribution - a recent long- game where I employed the Cozio to some success, though perhaps aided by my opponent to some slight degree...

As always, the Cozio game presented was interesting and in this case tactic-rich.

Hope you enjoyed - please offer analysis and/or place your own Cozio defence games in this thread so that we can discuss it's strengths and weaknesses.


That's a very interesting game by black. Congratulations. I specially enjoyed 12....e3! I haven't analized deeply the game but I should give that opening a try.

17.O-O-O was in my opinion, also a wise choice. You allready had a huge advantage and could afford the tempo for a stronger development.

btw, I don't think 14.Qe2 was a better option for white since black simply takes with the knight

Great game


Thanks Omicron, I've been enjoying the Cozio quite a bit - it no longer makes the Spanish game 'torture' for black lol .

And, ah- yes - how careless of me -of course 14. Qe2 ?? would have been an utmost blunder - I overlooked the knight when writing that post.

Otherwise, glad you enjoyed it, and I look forward to seeing other Cozio defence games posted up on here, and or I shall do the same!


That was a fantastic display from black, both from a tactical and strategical standpoint. I don't think that game is too representative of the Cozio Defense. Could we consider 4. c3 an innacuracy? It seemed to have doomed white in this game.


Actually Ytse - Ham - I would love to consider that move an innacuracy but as Jrobi (i.e. chess videos on you tube, been cited here before) has pointed out, it is the 3rd most recommended move for white in that position... believe it or not.

I'm not saying that I agree, but who am I to throw it in the face of established chess theory (which jrobi said he researched in depth for that particular video)

You are right though, this game is not necessarily representative of the Cozio, however, I must remark that I have had and seen several fascinating games with it.

In fact I am about to post another one, where I have a won sequence (it is a turn-based game), but I am waiting until my opponent resigns or until my conditionals kick in. It promises to be sweet though.

Personally however, I do consider c3 an innacuracy, and was very tempted to give it a ?! in the annotations..


To be honest I don't see what's so special and interesting about the cozio. To me it just looks like a solid, more defensive alternative that might help to avoid too much book study. It doesn't seem that interesting to me just because the knight goes to e7.



Well as promised, I have completed the game I mentioned (part of a current turn-based tourney I'm in) and it is ready to be posted!

I am particularly happy with the mating sequence involved - I put a lot or thought into it!

This game is particularly of note in the goal of this thread's discussion because it invovles what it debatably the best response for white to the Cozio i.e. 4. 0-0 (as confirmed by jrobi's analysis as well).

Well here it is :


I was a little rushed at the end while putting up the last game - I wanted to go through some of the mating variations. After move 20. the game is as follows:

 Only after much deliberation did I settle on move. 22. ... Bxd5 ! because it gave the most chances for a midgame mate.

based on this position, I found only three reasonable moves for white as a response, and all three seemed the end the game essentially for white. Ironically, this was especially the case for the move #22 chosen in the game i.e. taking my queen!

Let's have a look - variation #1 22. Nxh4 :

but there was also variation #2 (22. Qxd5 ) :
or of course there was also the varation #3, the knight move 22 . Nxd5 which was the most uncertain :
important to note was that the bishop was trapped on the queenside anyway and that had the game somehow gone into an endgame, I felt confident about a win given reasonable play.
What do you think, I mean I know white did not play ideally, but even still - I think this game is an example of why, even with white's 'best' 4th move in the Cozio line, black has excellent chances...
Of course added insights would be most helpful.

In your second game, 14. Bf4 should win easily for white.  I believe he's still forced to sac the light-squared bishop on b5, as you can move your queen to threaten his d4-knight, but he's up three pawns with a much safer king position after the sac.


Here is another contribution to the sting: a latest win with the Cozio, though in a 4 min blitz game.

It still has analytical value as some interesting and effective attacking patterns were employed (from a tactical analysis viewpoint), and yet there was some sound play and important positions explored by white as well.

Though white's play fel short of optimal, and though I botched the game on move #24 when I missed my chance to capture the queen via my previous tactical maneuvre, it was a fun and exciting game nonetheless, that ended on time, but the final position, and indeed all the moves up to # 24, say enough.

Take a look:


Another nice endgame win with the Cozio -this online game battle was very satisfying in all its stages, as I had an interesting conversion of a larger material lead into a smaller, yet safer, one. Though victory had to be proven in a distinguished endgame struggle -



in the second game after 11...b5 i think Ndb5 works. I would consider that position to be already won by white.


Here's the post (my first on this forum) which I meant to post earlier. :)

 While searching for Cozio Defence I found this thread which inspired me to sign up to chess.com and share a game I played recently on FICS. Not only did I surprise my oponent, but I also surprised myself by playing 3... Nge7.

I looked at my oponents rating and decided that I would stand a better chance with a less well known variation. I have not played the Cozio Defence much previously and hardly know anything about it.

The game was only 15 mins rapid so it is not at all accurate. I missed a simple mate in three on move 39 although I still had two minutes remaining on the clock. I was just playing moves quickly without thinking at that point - DOH! Anyhow the middle game may have some entertainment value at least.


Enjoyed looking at your games, thanks.


Despite the atrocious mistakes from both players, what surprised me is that the above middle game appeared to take on the nature of a Kings Indian Defence. Looking at it again I feel I could kick myself for many of my moves.

Now I would like to post another example of how not to play the Cozio:


That is indeed a nice checkmate at the end. Laughing


Sometimes,Aronian play Cozio. LEVON ARONIAN !!!

CID64 wrote:

Sometimes,Aronian play Cozio. LEVON ARONIAN !!!

Obviously better than my attempts lol.

Because I don't have much time to study openings, I figured that learning a few openings with less theory might be a viable compromise. However, it does concern me that such openings are seldom seen at high level.


I wouldnt trust anything Jrobi or any youtube chess coaches say...

Im too lazy to look but does anyone have any good positional games in the Cozio? (I dont mean this in a bad way). But this game was won by tactics and perhaps white being suprised by this opening and finding themselve sin unfamilar territory. I`d really like to see a few master games or even just some strong club players take on the Cozio.


I recently won another rapid game against a much higher rated player (2144 online elo) using the cozio. I didn't particularly feel comfortable with my position and the game was really won on time. Still the defence certainly seems to carry the element of surprise. Perhaps it could be a viable club player's opening, or if your name happens to be Levon Aronian. ^^

Here's another video for anyone interested in games with this opening:



Instead of posting my games I would like to post some positions from the main-lines of cozio where Black is in some sort of trouble.

Here is the first one:


Here is the second one: