I think we are talking about completely different things.

The MCO or any othe one-volume-opening-book is useful to get an small overview about every opening. It can help You to understand some of the main ideas and motives. The shown lines should be somehow typical so that You are not completely lost when You analyze Your games. Maybe this book will help You to build Your own repertoire. I like it very much and its alway my first choice when I like to try out something new.

A database shows everything that has been played. You will who played which move when and how successfull. But it wont tell You anything about the ideas behind the moves. This can be very usefull, especially when You play on a high level. But there is the danger that You may learn to play good moves without understanding what You are doing

A specialized book abou single openings is necessery so that You really understand the openings You use to play very often.

I honestly cannot understand why anyone would buy MCO or any other encyclodpedia of openings -- except for "Looks-good-sitting-on-the-bookshelf" value It just seems like it does less, worse, for more money than a good database. I'm using a FREE database program that lets me look thru lines that got played last week (using the FREE This Week In Chess download) -- I can sort to examine lines played by only 2600+ players, or only my favorite players... I can dynamically generate an "opening report" that tells me who is playing what line, how it does statistically, what the short wins (traps) are... etc. I repeat, this is all free . A chess engine (free) is integrated into the program so that I can also analyze lines myself.

What on earth does MCO have to compete with that?

If it's a big work on openings you want... Go for Watson's three volume How to Play the Openings books. They offer commentary and instruction on the openings, I haven't been thru them, but they look great and folks who have gone thru them speak highly of them. They seemed aimed at the club level player... I want them, just haven't figured out how to sneak them (or rather the credit card bill) past the wife.

And props to Miller, he gave Tal a great game. Naturally Tal comes up with Queen sac to save his bacon!

I bought a copy of MCO 15 when my only encyclopedia was a 40 year old BCO.  I like the book a lot, but if you want depth in EVERY opening, you should find a big computer database.  It only covers the main openings.  And the second minus, my book totally fell apart.  Now I have to make sure I don't lose any of the pages.

I've been using the Ninth edition since 1964, and am thinking that maybe there could be some additional opening ideas about. Tell me what you decide; the new MCO or a database!?

Tal ftw!

The MCO is a must for clean + sound chess. Fringe openings and wacky gambits are rarely covered in detail here...which was, at one point a reason I hated it because that's all I played :)

I think you'd be better off buying a big database. They have an opening tree, usually, and they contain much more information than a book like MCO. If you want proper analysis on a particular line, I think you'd do best to either buy a book or look around on chesspub.

I would not do it the way chessrohi suggest, unless you wish to reinvent the wheel (which may be fun).

It is probably the best "single volume" opening book.  Nick (deFirmian) is keeping it up to date.  A new volume will probably be out in 2-3 years.  Just to give you an idea, I have MCO 8 which I purchased in the 70's.

great game.

I have a copy of the book and I find it very useful. It's always nice to have an in hand reference as opposed to having to load a database (which may be down). It's easier to flip to a book page then it is to program in the 30 moves that have been played. There are no "surprises" in the book - meaning that you follow what seems to be a strong line (high win %) only to come up on a move that crushes you.

I would recommend having a copy for serious play, but to know if it's "right" for you, your local library should have a copy that you can test out.

I've got MCO 15. I like it pretty well, but idk if you would. Just sorta depends. It's pretty easy to use, and the notes are very helpful =)

i think that a good openings dbase is more likely to be up to date and easier to use than a book which is highly likely to be out of date by the time it is published.

couple the opening dbase with a regularly updated games dbase and you will be way ahead of any book.

I personally would just buy a good chess program and play openings against it. Look back at the games with the analysis function and also take your own notes about how the computer wins the games. You can also have the opening book opened in a window, so you can see a list of moves for whatever position you are playing. One way I get better at openings is to write down what problems I am having, such as a piece I'm finding difficult to put into play like bishops, and then see what the computer does in the same situation. I found that to be a much better way than trying to memorize lines because the computer will instantly show you ideas to capitalize on mistakes.