Back in the 1970's when I played on Oconto Falls High School's chess team, we had a copy of MCO-11, the "updated" version to this one. We made do with it, but the general consensus at the time was that MCO-11 had too many typographical errors in it and that MCO-10 was the superior work. Like MCO-11 and all the versions before it, MCO-10 uses English descriptive chess notation, i.e.: P-QB4, etc rather than the more "modern" algebraic notation that was then coming into vogue. I prefer English descriptive. Make from that what you wish.

Physically, it is a sturdy well-bound book and holds up well to travel, so if you want something to take to tournaments with you, this will fit the bill. Like all the versions of MCO, it is more of a reference work or an encyclopedia of chess openings, not an exhaustive reference work on any specific opening. As expected, the more popular openings like Ruy Lopez, Queen's Gambit and Sicilian Defense have more pages devoted to them as they have had much more "development" by masters in tournament play. You won't find many lines of the English Opening or the Reti System, but they are at least mentioned. The Blackmar-Diemer Gambit and other modern openings developed after the publication date are, of course, not referenced at all.

In my opinion, this version will serve the novice well and most likely will work for most people up to the master level. If you are among the best of the best, you want a more modern version to fill out your library, among other more specialized books, but there is no harm in having this one on the shelf next to it. ( )