If you are weak in the endgame, you must spend more time analysing studies; in your training games you must aim at transposing to endgames, which will help you to acquire the requisite experience.
Mikhail BotvinnikIt is a well known fact that almost all the outstanding chess-players have been first-class analysts.
Mikhail BotvinnikEvery great master will find it useful to have his own theory on the openings, which only he himself knows, a theory which is closely linked with plans for the middle game.
Mikhail Botvinnik