Instruct: Classify Amazon reviews into positive or negative sentiment
Query: Instruction in middle game strategies by former world champ.

Euwe shoots for the amateur and is right on target. 'A' players and below find the weak spots in Master strategy and gain confidence in Euwe's text that illustrates that amateurs can defeat stronger opposition by excluding inferior moves from their middle game play. The first in a genre that has been duplicated for twenty years but not exceeded. A current pretender is Jeremy Silman's 'Improve Your Chess'.