Someone once asked Richard Reti how many moves in advance he routinely calculated, and he famously answered, "none." That was hyperbole. Of course, he could calculate many moves in advance, when he needed to. The point he was making was that chess, at a certain level, and I'm going to stick my neck out and state a number (later on), is played on strategic principles. Calculation--I go here, you go there, then I go here, then you go there, etc.--is error prone and exhausting. One tends to get lost in variations wh/ lead nowhere or to blunders or to positions where one cannot see either any advantage or disadvantage. As Reti also remarked, if you cannot correctly judge the position you are in now, you won't be able to correctly judge a position you calculate, five or ten or twenty moves ahead.
Maki1 asked for a game against a higher-rated player, posted below. I include notes about my thought processes and the principles I consciously applied as we played. After an inconclusive opening, in wh/ I wrested a pawn advantage, we reached and endgame with K,R,B,N each, pawns on both wings, and, significantly, opposite-colored bishops. So, I dug into my memory of one of my favorite books on chess theory, Capablanca's Chess Fundamentals for some insight how to play the endgame. Capablanca was awesome in all phases of the game, but he was particularly noted for his endgames.
A one-pawn advantage in an endgame with rook, knight, pawns on both flanks, and opposite-colored bishops, is no simple matter to conduct. Simply advancing the extra pawn is not guaranteed to win; some preparation will be necessary. The weaker side should try to blockade the extra pawn, ideally, with either the knight or the bishop directly in front of the extra pawn. The reason being that the bishops's and the knight's range of mobility is not restricted by the opponent's pawn. Whereas, if a rook is placed in front of the opposing pawn, its range of mobility is severely restricted, the more so the farther advanced the pawn is. In the game in hand, w/ bishops of opposite color, if the weaker side can place his own bishop directly in front of the advancing pawn, then the stronger side cannot dislodge it with his own bishop. The blockading bishop can be dislodged only w/ some other piece, a knight or a rook, or a pawn on an adjacent file. Hence, the stronger side will want to avoid two scenarios: letting his extra pawn become isolated, and trading off all the other pieces leaving only two bishops of opposite color. These were some of the general principles wh/ I kept in mind in the following game, guiding me through a multi-piece endgame.
The reader will note another recurring principle, wh/ I also gratefully credit to Capablanca's excellent book and examples from his games: that of restricting the mobility of one's opponent's pieces. In the following game, I had occasion to trap a knight on the edge of the board--it is a tactical trick one should commit to memory, should the opportunity arise to employ it.
A stronger player than myself would have found a quicker route; I played cautiously, carefully laying the groundwork before committing my extra pawn to the final push--slow constriction suits my style of play more than an Adolf Anderssenian mad dash for the smothered mate.
To my opponent, thank you for the challenge and for giving permission to post the game here, w/ notes. Holding on for 45 moves with a 400-point rating differential is an achievement in itself. I know it is not soothing to one's ego to lose games, but, to quote Capablanca, "I learned more from the games I lost than from those I won." I wish you success cracking the 1800 barrier! The joy of chess increases as one becomes able to formulate long-range plans and see them executed over the board.
I will close with a quote from Kasparov: "A game of chess is like trying to paint a picture with someone tugging at your sleeve."