1.  K-Q4, P-B4ch; 2.  K-B4, K-B3; 3.  P-B3 K-Kt3; 4.  K-Q5, P-B3ch; 5.  K-B4, and wins.

Doubled pawns are a drawback, even when not isolated, should there be no way of obtaining a passed pawn by exchanging them against a smaller number of single pawns.  This is illustrated in Diagram 66, in which Black wins because the three pawns on the King’s side hold up the four White pawns and the Black King can assail the White pawns from the rear,

---------------------------------------
8 |    |    |    |    |    |    |    |    |
|---------------------------------------|
7 |    |    |    |    |    | #P | #P | #P |
|---------------------------------------|
6 |    |    |    |    |    |    |    |    |
|---------------------------------------|
5 |    |    |    |    |    | ^P |    | ^P |
|---------------------------------------|
4 |    |    | #K |    |    |    | ^P |    |
|---------------------------------------|
3 |    |    | #P |    |    |    |    |    |
|---------------------------------------|
2 |    |    |    |    |    | ^P |    |    |
|---------------------------------------|
1 |    |    | ^K |    |    |    |    |    |
---------------------------------------
A    B    C    D    E    F    G    H

Diag. 66

the White King being fettered by the necessity of capturing the QBP.  The proper formation for the Black pawns would be at B3, Kt2, R3, after which White cannot force a pawn through by playing P-B4 and P-Kt5, as Black can refrain from making any exchange.  Black could not afford to leave the pawns where they are, because even if there were no White pawn at B2, White would, by playing P-Kt5, threaten to win in the following way: 

1.  P-Kt6, BPxP; 2.  P-R6, and P-B6, etc.; or 1. ...  RPxP; 2.  P-B6, with P-R6, etc.  In a game Ed. Lasker-Moll (Berlin championship, 1904), from which the position is taken, Black played P-R3 in order to obtain the formation mentioned above, and White resigned after 2.  P-B4?  P-B3, P-Kt5, K-Q5.  There was, however, a pretty win after Black’s P-R3, namely:  2.  P-B6, PxP; 3.  P-B4, K-Q5; 4.  P-Kt5, BPxP; 5.  PxP, K-K4; 6.  PxP, K-B6; 7.  K-B2 and Black is lost, because his own pawn obstructs the square B2, and the King must release the square Kt2, after which the White pawn queens.

This winning combination, however, is only an interesting exception to the rule that positions of this kind are generally won by the side which possesses the passed pawn.  In this particular case Black could have made the position secure by obtaining the ideal position of B3 Kt2 R3 for his pawns earlier, before the White pawns could advance so far.  In the position of Diagram 66 Black could still have won by playing P-B3.  After 2.  P-R6, PxP; 3.  P-B4, K-Q4; the Black King has time to overtake the passed pawn which results on the Bishop’s file.

To conclude the study of pawn endings with an equal number of pawns on either side, we will discuss Diagram 67,