H UMEDAL DE G IMILEO

The "two Bishops" are the reason for the old advice not to be too ready to exchange a 1i for a � in the opening. Beginners naturally find this advice difficult to understand when, at the same time, they are told that the A and � are approximately equal. The point is, however, that the exchange of 1i for � early in the opening will deprive you of "the two Bishops" while leaving your opponent with them. If, however, one A on each side has already been exchanged, it does not matter about parting with the other, and an exchange must be judged on its merits.

Before smugly congratulating oneself on the possession of two As, or before gleefully playing for the possession of them, there are two questions to be asked:

1. Are they both mobile?

2. Has the enemy a very powerful �?

Considering the first question, remember that a A cannot be mobile if the squares on which he moves are clogged by his own fts, and those fts are blocked. Perhaps the chief disadvantage of an isolated ft on d4/ d5 is that it considerably enfeebles the 'l!¥-A by obstructing both the long diagonals which intersect on that square. A couple of lis like best of all to see no ft of any sort on e4, d4, e5, or d5. On the other hand, one can't pander to these dignitaries to the detriment of one's forces as a whole, and the value of a pawn center is well known.

The second question is equally important. A ft -supported, unassailable � on e6/e3 or d6/d3 is well known to be so powerful that it usually pays the enemy to give up a § to get rid of him (provided a ft is obtained into the bargain). It follows that such a � must be stronger than any A -barring freak positions. So if you have two As and the enemy has such a �_' you can write the two As off, as one will have to be used to exchange off the �. That is, unless you yourself have a � for the purpose.

A ft -supported, unassailable � on e5/e4 or d5/d4 or f5/f4 is usually not quite as strong as on e6/e3 or d6/d3-except on f5/f4 against an exposed �. But much the same principle applies: the � usually has to be got rid of, so if you have two As and no other minor pieces you are likely to have to part with one A.

But positions arise where, even though the enemy's �s do not appear to be well placed at the moment, they can get the upper hand of the two As. The following opening play from the New South Wales Championship of 1930, which showed the high strategical ability of M.E. Goldstein, is a remarkable case in point.

M.E. Goldstein-Purdy 1. d4 Nf6 2. Nf3 e6 3. c4 d5 4. Bg5 5. e3 6. Nc3 7. Rcl Nbd7 Be7 0-0

tion" in the Queen's Gambit Declined.

7. ... b6

Old-fashioned, though not by any means bad. The noncommittal ... c6 is usu­ ally preferred. 8. cxd5 exd5 9. Bb5 Capablanca's move. 9. Bb7 10. 0-0 a6 11. Ba4 c5

This was the "book" move until my suggestion of transposing with 77 ... RcB was adopted. Mterwards, I suggested an alter­ native in 70 ... c6instead of 70 ... a6. The final

verdict has not been given. 12. Bxd7!

This was original here. White breaks the old maxim about not making a volun­ tary early exchange of A for ltl.

Chess players may be divided into three classes: those who don't know the prin­ ciples, and are therefore very weak; those who know the principles, and are less weak; and those who know how weak the prin­ ciples are, and are strong.

12. ... Qxd7

Not 72 ... Nxd7 73. Bxe7 Q!e7 74. dxc5 Q!c5 because Black then has ( 1) an isolated d- ft ; and (2) a A obstructed by it.

13. dxc5 bxc5

Black now has the "hanging pawns," which are often well described as "both weak and strong." They are weak because they need pieces to protect them, and strong because they form a phalanx that controls a lot of the center. If it were Black's move, he would have a good game with his two As, but it is White's move, and a certain tactical possibility turns the scale the other way. Hence the fallacy of judging a position on its general appearance without looking to see if the side whose turn it is to move has some special opportunity.

14. Na4! Qb5

White had a double threat: a fork and a ft capture.

15. Bxf6! gxf6

White has parted with his other A. Evidently wisely, as he wrecks Black's �­ side in compensation. True, there is danger of Black building up an attack per medium of the opened g-file if permitted, but he will not be permitted.

16. Nh4!

Truly a remarkable position. White has both ltls in their traditionally worst situa­ tion (edge of the board), and Black has the traditionally powerful two As, and yet White has the advantage. Black's disabilities are six weak fts and a weak �.

16. Bc8!

17. Nc3! Qxb2

18. Rc2 Qb7

19. Nxd5

And now the point. Black cannot even retain his two As, White's ltls having be­ come so menacing. The sequel was slightly amusing: 19 ... Kh8 20. Nxe7 Qxe7 21. Qh5 Be6, and now the plausible 22. Rxc5? White should have been content with 22. Q!c5, getting a superior endgame, for now Black had an opportunity-which he missed­ of turning the tables and gaining a winning advantage by 22 ... Bg4! 23. Qj5 RfdB!

One cannot too frequently point out the moral that the price of success in chess is eternal vigilance. On this occasion, how­ ever, Black missed the chance and White went on to win.