First thing...the book is in descriptive notation, but for old timers that's not problem. If you don't know descriptive notation you should learn it because doing so would make a lot of excellent old books available. The other thing I disliked is that, like Reinfeld, the authors don't give the player's names, dates or events...to protect the guilty, I guess. It's not important, but I like to know that stuff. It's mostly a good book but Euwe made some comments on the openings that are pretty dated.
The book contains 25 games and focuses on how an amateur's weak moves are punished by masters... premature attacks, crude attacks, neglected development, neglecting to deal with a well posted N, open lines, that sort of thing. In many ways the book is similar to Jeremy Silman's The Amateurs Mind where he looks at positions from games between him and his students. Long variations are avoided and there are lots of verbal descriptions which makes it very helpful for lower rated amateurs to follow.
The games start out in order of the amateur's skill level starting with beginners up to maybe the 1800-1900 level. There is a brief introduction to each game that explains the basic concepts point by point.
Naturally, the games aren't perfect and in some cases they are downright horrible, but that's how amateurs play, so there is some value in looking at those games. Maybe even more than there is looking at high level GM games. That's because that's how we amateurs play...horrible and the miniscule subtleties of GM play are usually lost on us anyway. That's why I always liked tournament books that contain all the games from an event. I like looking at the games of the tailenders just to see how ordinary master really play...sometimes it's encouraging to know they are often far from perfect!
One of the more interesting games was game 24 which featured the Master, as white, playing King's Gambit, Allgaier Gambit. I got the impression that Euwe, in trying to show the superiority of the master's play, did not give sufficient credit to black's play which was pretty good up to his 9th move which allowed the Master to equalize. After that, the amateur didn't make any gross blunders, but instead made a series of small mistakes that soon lead to him having a lost position. Let's take a look at it.