As a rule, so-called "positional" sacrifices are considered more difficult, and therefore more praise-worthy, than those which are based exclusively on an exact calculation of tactical possibilities.
Alexander AlekhineFor success I consider three factors are necessary: firstly, an awareness of my own strengths and weaknesses; secondly, an accurate understanding of my opponent's strengths and weaknesses; thirdly, a higher aim than momentary satisfaction. I see this aim as being scientific and artistic achievements, which place the game of chess on a par with other arts.
Alexander AlekhineI consider chess an art, and accept all those responsibilities which art places upon its devotees.
Alexander Alekhine