Two Weaknesses – Principle of Two Weaknesses
Two Weaknesses (Principle of Two Weaknesses)
Definition
The Principle of Two Weaknesses is a strategic guideline stating that an attacker usually needs to create and exploit at least two separate targets in the defender’s position—such as a vulnerable pawn, an exposed king, or a weak square—before a decisive breakthrough becomes possible. One weakness can generally be defended; two (or more) stretch the defender’s forces so thin that something eventually collapses.
How the Concept Is Used
- Endgames: In technical endings, the superior side shifts play from one flank to the other until the defender can no longer maintain both fronts. Classic examples involve creating a distant passed pawn on one wing and then invading on the other.
- Middlegames: Attackers may first fix a structural defect (e.g., doubled pawns) and then open lines against the king. Only when two weaknesses coexist does the position often cross the “tipping point” from holdable to lost.
- Time Management: Players with an extra 10 minutes on the clock may still prefer to simplify into an ending where they can apply the principle calmly, rather than try for an immediate tactical knockout.
- Engines & Evaluation: Modern engines instinctively apply the principle, shuffling pieces until a second target appears, at which point their evaluation jumps.
Strategic & Historical Significance
The idea is attributed to Wilhelm Steinitz, the first official World Champion, who insisted that
winning requires accumulating small advantages
.
Later champions—especially José Raúl Capablanca and Mikhail Botvinnik—turned the
abstract dictum into a practical end-game technique, making the principle a cornerstone of classical chess
strategy taught in virtually every manual since 1900.
Illustrative Examples
1. Capablanca – Tartakower, New York 1924
Position after 33...Kg7: White: King g2, Queen e3, Rooks d1 & f1, Knights f4 & e5, Pawns a2 b2 c3 f2 g3 h2. Black: King g7, Queen c7, Rooks d8 & e8, Bishop g8, Knight f6, Pawns a7 b6 c5 f7 g6 h7.
Weakness #1: the backward pawn on c5.
Weakness #2: the kingside light squares around g7–h7, especially once White plays 34. Rxd8 Rxd8 35. c4!.
Capablanca first fixed the queenside pawn, then switched to a direct attack on Black’s king, finally winning on move 54. The defender could parry either target in isolation, but not both simultaneously.
2. Botvinnik – Alekhine, AVRO 1938
In a heavy-piece endgame, Botvinnik obtained a distant passed a-pawn (first weakness) and then pried open Alekhine’s king with g- and h-pawn thrusts (second weakness), eventually forcing resignation despite material equality. The game is often cited in textbooks on how to convert a slight space edge into two concrete structural defects.
3. “Switchback” Maneuver – Petrosian – Spassky, World Championship 1966, Game 10
The 9th World Champion, Tigran Petrosian, tied down Spassky’s pieces to the weak d6-pawn for over 30 moves.
Only after securing a queenside breakthrough with b4–b5 (second weakness) did he liquidate into a won rook ending.
Spassky notably remarked that he felt he was defending two games at once
.
Typical Methods of Creating a Second Weakness
- Fix one pawn with a piece blockade, then open a second front with a pawn break (e.g., h4–h5).
- Force the defender’s king into a vulnerable corner, then switch the major pieces to the opposite wing.
- Create a distant passed pawn to drag enemy forces away from the real point of invasion.
- Exchange minor pieces to enhance the power of long-range rooks/queens against multiple targets.
Interesting Facts & Anecdotes
- The term is so ingrained in Russian chess literature that coaches shorthand it as the “Dvukhslabost’ rule.”
- In training camps, Garry Kasparov forced juniors to play out queen vs. rook endings where the winning technique hinges on manufacturing two weaknesses: the rook and a mating net.
- Computer tablebases confirm the principle mathematically: many theoretically drawn pawn endings become lost only when the stronger side forces the defender to guard two pawn fronts simultaneously.
Take-Away
Whenever you hold an advantage yet see no immediate breakthrough, ask: “Where can I create a second weakness?” The answer often converts a small edge into a full point.