Alexei Kosikov's Elements of Chess Strategy is an extremely well written book and was written for the above average or above mid-range players. Botvinnik's most famous positional move of Qe3 in his game against Sorokin in the USSR Championship, Moscow 1931 is lucidly explained, as is Fischer's Knight gallop to beat Spassky in the first match of their Yugoslavian contest in 1992. Kosikov illustrates a number of useful strategic concepts with many examples....more than Sunil Weeramantry's " Best Lessons of a Chess Coach". Less wordy than Silman's "How to re-assess your chess", you'll quickly get the ideas Kosikov wants you to understand !!
Check it out.
For a sample of some of the pages, please visit :