Forcing Chess Moves: The Key to Better Calculation

By Charles Hertan and Joel Benjamin

Every chess fan marvels at the wonderful combinations with which famous masters win games. How do they find those fantastic moves? Do they have a special vision? And why do computers outwit us tactically? This rich book on chess tactics proposes a revolutionary method for finding winning moves. Charles Hertan has made an astonishing discovery: the failure to consider key moves is often due to human bias. Your brain tends to disregard many winning moves because they are counter-intuitive or look unnatural. We can no longer deny it, computers outdo us humans when it comes to tactical vision and brute force calculation. So why not learn from them? Charles Hertan’s radically different approach is: use computer eyes and always look for the most forcing move first. By studying forcing sequences according to Hertan’s method you will develop analytical precision, improve your tactical vision, overcome human bias and staleness, enjoy the calculation of difficult positions. This New and Extended Fourth Edition presents 50 pages with new and instructive combinations. With a foreword by three-time US chess champion Joel Benjamin.

• Language: English
• Publisher: New in Chess
• Release date: Sep 1, 2019
• ISBN: 9789056918576

Charles Hertan

Charles Hertan is a FIDE master from Massachusetts with several decades of experience as a chess coach. He is the author of the bestselling Power Chess for Kids series.

Book preview

‘Ex’.

CHAPTER 1

Stock forcing moves

Study material

Beginners typically start their tactical education with basic stratagems like fork, pin, and skewer. With further study, they encounter standard combinations like the classical bishop sacrifice, double bishop sacrifice, and Philidor’s (‘Smothered’) Mate, which can and should be studied in any good basic tactics book (I recommend the classic Art of the Checkmate by Renaud and Kahn).

Later, as players gain some experience and absorb a large number of master games, a variety of ‘stock’ themes, or typical winning sacrifices, become familiar. In this first chapter, we look at typical stock tactics with the rook, knight, bishop and queen. Chapter 2 examines winning stock attacks against vulnerable squares around the enemy king. By helping you to better understand these crucial weapons in the master arsenal, these two chapters introduce you to the power of FORCING MOVES.

By focusing on the role of BRUTE FORCE CALCULATION and UNEXPECTED MOVES in implementing these sacrifices, we also begin the process of honing your COMPUTER EYES. Strong masters develop a ‘radar’ for these recurring types of combinations through study and experience, which helps them to quickly find the right continuation in the heat of battle. As you absorb the stock forcing moves used by the pros, and learn to apply them in your own games, you will gradually sharpen your own instincts.

We are talking about stock mates and sacrifices involving the rook, knight, bishop and queen. But what about the king and pawn, you may ask? Does the author neglect the contributions of these noble pieces? Well, the king is a very fine attacker, especially in the endgame; but he cannot effectively sacrifice himself… so sorry, I cannot recall any important stock positions starring the monarch. As for the pawn, it generally plays a supporting role in the stock motifs of other pieces, except for the special case of PROMOTION, which is so important that we will examine it deeply in the context of later chapters.

A) Stock mating patterns involving the rook

Back rank themes

This is the first stock mating pattern that most players discover, yet it remains highly important at all levels, recurring in many creative and disguised forms, in analysis and actual play.

FCM 1.1

Belov-Osachuk

Soviet Union 1965

1.♕f8+! ♔xf8

1…♔g6 2.♕h6#.

2.♗h6+ ♔g8 3.♖e8#.

Computer eyes can help you find this pretty combination in a heartbeat. The queen sacrifice is shocking, but it is also the MOST FORCING MOVE on the board (allowing just two legal responses), which you will already recognize from the Introduction as the move which must be looked at first!

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Here is a fancier version of the same idea:

FCM 1.2

Netto-Abente

Paraguay 1983

Two major pieces are a small price to pay, to have the bishop land on h3 with check:

1…♖e1+ 2.♔g2 ♖g1+!! 3.♔xg1 ♕e1+ 4.♔g2 ♕f1+! 5.♔xf1 ♗h3+ 6.♔g1 ♖e1#. Again, the most forcing options held the key, and there was no need to look any further!

Most often the bishop on h6 does not appear by means of a flashy sacrifice; scores of back rank ideas are based on the presence of a bishop or pawn on f6 or h6, blocking the king’s g7 escape hatch:

FCM 1.3

Radevich-Donskikh

Soviet Union 1972

The stock shot 1.f7+!, mating on f8 after either 1…♗xf7 2.♖a8+ or 1…♔xf7 2.♖f1+ ♔g8 3.♖f8#, is not a trivial tactic to foresee, without having developed one’s computer eyes. But perhaps you already discovered this beautiful move on your own, if you are a quick learner and already in the habit of analyzing the most forcing move first!

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A queen on h6 is an especially dangerous guardian of the g7 escape square, since the defender must also worry about incursions on f8, f6 or h7:

FCM 1.4

Oll-Cvitan

Eupen (rapid) 1995

1.♖d7!

Not the most forcing option (that honor would belong to 1.♕f8+, 1.♕g7+, or 1.♖d8+), but the only one that wins! Remember our introductory discussion: the most forcing move usually loses, but is still the one which must be looked at first. If you still doubt this, reread the last few pages!

The black queen falls, since 1…♕e8 (to prevent 2.♕f8#) is met by 2.♕f6+ ♔g8 3.♖d8 1-0.

FCM 1.5

Karasev-Klaman

Leningrad 1967

White exploits Black’s back rank woes creatively to set up a mating attack:

1.♖e6! ♕d8

Again, the queen must guard against 2.♕xf8#.

2.♖g6!

Did you overlook this forcing move because it looks impossible? Chapter 4, on SURPRISE FORCING MOVES, will help you overcome this bias!

2…♖g8 3.♖xf7

The attack shifts from g7 to the sitting duck on h7.

3…♖d1+ 4.♔h2 ♕b8+ 5.g3 1-0 The white king walks toward the rook.

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A bishop (or other piece) blocking the king’s escape hatch at h7 can have the same effect of creating a back rank liability for the defender:

FCM 1.6

Topalov-Morozevich

Cannes 2002

1.♗e4!! A fantastic feat of computer eyes! Yes, attacking all three black pieces is very forcing, but since you are not a computer or world champion, you probably need to work on your SELECTION skills to even consider such a surprise forcing move!

1…♖xb5

There is no escape, e.g. 1…♘xf2+ 2.♔g2 ♖ee8 3.♖xb8 ♖xb8 4.♔xf2.

2.♖a8+! 1-0

Here is a different type of stock back rank theme, in which the king is first ‘kidnapped’ into mating position:

FCM 1.7

Askelof-Svensson

correspondence game, 1983

1…♖e1+! 2.♖xe1 ♕g1+!

A winning ZWISCHENZUG or ‘in-between forcing move’, a tactic we will explore much more deeply in Chapter 8.

3.♔xg1 ♖xe1#.

Take note: all of Black’s moves were surprising and beautiful, but also 100% forcing, and thus among the first options needing to be considered.

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In case you still have any doubt that studying stock tactics will win you more games, check out a more recent example. Championship contender Aronian probably wished he’d packed a copy of FCM in his travel bag after this debacle:

FCM 1.8

Aronian-Van Wely

Wijk aan Zee 2014

The wily Dutchman was no doubt ready to stop the clocks after 1.♕xe6 or 1.♘g5+, when his last prayer was answered by 1.exf4?? ♗d4+! and it was Aronian who had to concede in view of 2.cxd4 ♕b1+ 3.♗e1 ♕xe1+.

FCM 1.9

Morozevich-Bologan

Sochi 2004

Having fewer escape options, a king in the corner is even more subject to ‘kidnapping’:

1.♕h8+! ♔xh8 2.♖xf8+ ♘g8 3.♗e5+ 1-0

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A SENSITIVE BACK RANK calls for heightened creative alertness to the endless array of ‘surprise tactics’:

FCM 1.10

Ashley-Kortchnoi

San Francisco 1995

If eyes could smell, computer eyes would smell blood here! Black is very active and White’s back rank is vulnerable. Soon even the ♖h4 will join the fray!

1…♘d2!

Exploiting the ‘interference theme’ 2.♖xd2 ♕c1+!.

2.b3

The white queen is overloaded after 2.♕xd2 ♖xd4! and he will have to give his rook on h1 after 2.♗d3 ♕c1+! 3.♗b1 ♖xd4!, but now mate comes on the a-file!

2…♘xb3+! 3.axb3 ♖c5! 0-1

4.♖xb4 ♖a5+ etc.

FCM 1.11

Kharlov-Franco Ocampos

Zaragoza 1994

A forking move is justified by deadly back-rank pins:

1.b4! ♗xb4

On 1…♕xb4, the skewer 2.♗c3! exploits the d-file pin.

2.♕xc8! 1-0

Crushing is 2…♖xc8 3.♖xc8+ ♗f8 4.♗a3! with too much wood for the queen.

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In master play, a strong secondary threat, such as a knight fork or a mating idea, usually works together with back rank motifs:

FCM 1.12

Larsen-Ljubojevic

Milan 1975

1…♕h4!

A prime forcing option which must be examined even though it ‘drops material’. Before rejecting such a move you must always try to look one move deeper, for the most forcing follow-up – often your opponent won’t!

2.♕xe5

The gift must be accepted; if 2.h3 ♕xh3+ 3.♔g1 ♗h2+ 4.♔f2 (4.♔h1 ♗g3+) 4…♕g3#. But now White has too many problems on g2 and the back row.

2…♕f2! 0-1 On 3.♖g1 ♕xg2+! 4.♖xg2 ♖c1 mates.

Computer eyes must begin with looking out for this crucial stock pattern – the ‘diversion sacrifice’ which draws off a key back rank defender.

FCM 1.13

Rada-Kostal

Prague 1942

White sets up a ‘CROSS-PIN’ of the black queen, to attack both g7 and the back rank:

1.♖xb2! ♖xb2 2.♕d4 ♕e5

Black foresaw White’s sacrifice and prepared this seemingly tight defense. White contemplated the vulnerable back rank and looked one forcing move deeper:

3.♖e1! 1-0 The queen is diverted from one of the mating squares g7 or e8.

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DIVERSION SACRIFICES may also occur when a piece must guard another unit, as well as the back rank:

FCM 1.14

Anand-Hou Yifan

Wijk aan Zee 2018

White’s only meaningful advantage here is the advanced passed pawn, but this example illustrates well why this is often enough. Even when the pawn seems contained, it controls key squares in the enemy camp, which White exploits to perfection with a crucial stock back rank diversion trick: 1.♖d7! when 1…♕xc6? allows 2.♖d8+!, winning the queen. White exploited the back rank motif again after 1…♕a5 with 2.c7! (2…♖xc7 3.♖d8#), and now the passer was simply too strong after 2…♖f8 3.♕e7, threatening 4.♕xf8+ or 4.♖d8: 1-0.

FCM 1.15

Mieses-Reshevsky

Margate 1935