Purdy Wisdom

      Playing over master games is one of the best ways to improve, but only of you cover the moves.  Get a card and cut an aperture in it about as long and wide as a printed move of one side of a game.  When you have decided what you would play and wish to compare your move with the text, slide the card down until the move shows.  Then, after making a comparison, slide the card across until the other side’s move shows.  Don’t ponder in advance about both side’s moves-only one side’s.
       If you like, you can keep a record of the number of moves you get the same as in the text and watch it rise.  It won’t rise evenly, as some games contain many obvious moves-others not.  But if you take an average over ten games, your average for the next ten games will be higher. And so on.

It is axiomatic that positional play is concerned only with small advantages and disadvantages.  Big ones naturally occur only through forcing moves, i.e. combinations.  But because the great majority of chess moves have to be positional, positional play is, taken all around, of roughly the same importance as combination play.