28 September 2014

Playing all Night

Sometimes I play online blitz or bullet all night long. Sometimes this reckless behavior stems from trying to swing my way through a slump.* After I lose several games that I should have won, I keep playing until my performance improves. Other times I play all night because I am angry and cannot sleep, or I cannot sleep because there is trouble in the neighborhood. Maybe sleeplessness stems from my dogs being agitated and noisy, or due to travel or stress.

Last night I had a three hour blitz session relating to care some family responsibilities.

These all night sessions generally produce more losses than wins. My errors are often elementary. These games fill my database with intructive errors that can be used teaching beginners.

On my previous move prior to this position, I could have snatched the pawn.

Black to move

Instead of moving my king, forcing my opponent's king to b5, I played Qb8 and stalemated my adversary.

This position is less elementary.

Black to move

One move gives me an advantage, all others lose. My opponent drew the game with repetitive checks after my Kf7.

In this position from an Exchange French, Nxe5 is simple and correct.

Black to move

I played Nxd4 and quickly found my position hopelessly lost.

Here I had an advantage against a player rated more than 400 Elo above me.

White to move

I considered 42.Kxg5, but played the inferior 42.Kh3. After 42...Re3 43.Kg4  Rxb3 44.Rxa5 Rb2, I stillcoul have taken the g-pawn and been better.

White to move

Instead, things remained balanced with 45.Kf5 Rxh2 46.Ra7+ Ke8 47.d6 Re2 48.Kf6 h3 49.Rh7 h2

White to move

Here 50.a5 is the only move that maintains equality. Alas, the last few moves have been sheer panic after blowing a nice position. I played 50.Kxg5 and resigned a few moves later.

Happily, I won six of the next seven games. The one blemish in that series in the stalemate above.


*A baseball metaphor. See "You just swing through it."

17 September 2014

Losing Time

Time, that is, efficiency, is a central strategic and tactical element in the game of chess. A player who wastes time quickly finds him- or herself in a worse position even without material loss. Moving one piece repeatedly in the opening usually wastes time.

Two games illustrate this problem. The first was played against some version of Crafty embedded in the Chessimo training app for iPad more than a year ago. The second was played on the Game of King's iPad app and finished yesterday. In both cases, Black was much worse a few moves into the game as a consequence of moving a bishop several times.

Stripes,James -- Crafty (Chessimo) [A46]
Rating Estimation, 01.02.2013

1.d4 e6 2.Nf3 Nf6 3.e3 Bb4+

A silly check.

4.c3 Bd6?

4...Be7 was sensible.

5.Bd3 0–0 6.0–0 Be7 7.Nbd2 d5 8.Re1 Nc6 9.Qc2 Bd6?!

Another time wasting move that makes White's plan even better than it would have been. The bishop is now vulnerable to attack.

10.e4 dxe4 11.Nxe4 Nxe4 12.Bxe4

Black to move

12...Kh8?

I suspect that Crafty fell prey to a limited search horizon, believing that it could trap the bishop if White played as he did.

13.Bxh7 g6

White's bishop is trapped.

14.Bg5?

White should have played 14...Ng5.

14...Qe8??

Black recovers from early errors with another bishop move: 14...Be7. Instead, Black has moved into a forced checkmate.

15.Bf6+ Kxh7 16.Qe4 Bf4 17.Qxf4 Qd7 18.Qh4+ Kg8 19.Qh8# 1–0


Stripes,J (1974) -- Nomen Nescio (1929) [D24]
Rated Match Game of Kings - Online Chess, 16.09.2014

1.d4 d5 2.Nf3 Bf5

Not a terrible move, but not best either. 2...e6, 2...c6, 2...Nf6 are all better.

3.c4 Nf6 4.Nc3 dxc4 5.e3 Be6?

Black moves the bishop a second time.

6.e4 Bg4?

And a third.

7.Bxc4 Bxf3 8.gxf3 e6

White to move

White already has a clear advantage. The rest of the game demonstrates White getting an easy win despite playing less than optimal moves.

9.d5 e5 10.Qb3 b6 11.d6 Qd7 12.dxc7 Qxc7 13.Bg5 Nc6 14.Rd1 Nd4 15.Nb5 Nxf3+ 16.Ke2 Qb7 17.Qxf3 a6 18.Nc3 b5 19.Bd5 Nxd5 20.Rxd5 f6 21.Bxf6 gxf6 22.Qxf6 Bg7 23.Rxe5+ Kd7 24.Re7+ Kc8 25.Qe6+ Kb8 26.Rxb7+ Kxb7 27.Qd7+ Kb6 28.Nd5+ Kc5 29.Qxg7 Rhe8 30.Qc7+ Kd4 31.f3 Rac8 32.Rd1# 1–0


15 September 2014

Blitz Woes

Over the last few weeks, I have blown many wins and draws in online blitz. I also have had a few games handed to me by similar errors by my opponents.

Black to move

Black should hold with 43...Ke7, but I played 43...Nc7 and after 44.Kd6 Nb5+ 45.Bxb5 axb5 we reached a pawn ending that was hopeless for me.

White to move

Black has nothing if the bishop remains on the c1-h6 diagonal and avoids exchange for the knight. Nor can White make progress. But, after my opponent's 33.Be1, I gained an advantage. 33...Nc4 and White's king had to move.

White to move

I played the obvious 19.Rxd4, but my opponent would have been no worse after 19...cxd4 20.Qxe7 Rxc1+ 21.Kf2 Rc2+. Instead, he played 19...f6. After 20.Qb3+ Kh8 21.Rd6 fxe5 22.Re6 Qc7 23.Rxe5 I had a one-pawn advantage and went on to win.

12 September 2014

La Bourdonnais's Infantry

McDonnell -- La Bourdonnais 1834

In game 21 of their first match, Alexander McDonnell's knights prevailed (see "McDonnell's Cavalry"). In the next game,Louis-Charles Mahé de La Bourdonnais gave a demonstration of principles set down eighty-five years earlier in L’analyze des échecs (1849) by François-André Danican Philidor. His pawns decided the battle.

Occasionally, chess writers assert that Philidor's ideas concerning pawns were poorly understood until revived by Wilhelm Steinitz. For example, Dražen Marović offers this historical note in Understanding Pawn Play in Chess (2000).
Not many players followed in Philidor's footsteps. One must advance well into the next century to see another great player, Howard Staunton, exploring such niceties as the restrained engagement of pawns, play against doubled pawns or blockade. (5)
Similarly, in My Great Predecessors (2003) Garry Kasparov suggests that Philidor "was too far ahead of his time: no one was able to play successfully in the manner proposed by him" (13). He observes that La Bourdonnais had studied Philidor's text, but did not adopt his principles.
Although he had studied Philidor's L'Analyse, he nevertheless played in a different, intuitive attacking style, in keeping with his own temperament. (14)
Although we do not see the defensive technique against pawns that Marović asserts would emerge a decade later with Staunton, La Bourdonnais does offer several games that demonstrate the offensive power of pawns. Did he use his intuition, as Kasparov seems to suggest, to see through to the end in the present game? Or, did he calculate?

La Bourdonnais had already won the first match decisively before this game was played. Nonetheless, the players continued until twenty-one decisive games had been played.


Excluding draws, La Bourdonnais leads 13-4. The French player's win in game 22 makes it the eighteenth decisive game.

Beginning with the post, "Three Fighting Draws," I have been going through all of the games in this match. I offer my analysis without reference to engine evaluations.

McDonnell,Alexander -- De Labourdonnais,Louis Charles Mahe [C33]
London m1 London (22), 1834

1.e4 e5 2.f4 exf4 3.Bc4 Qh4+ 4.Kf1 g5 5.Nc3 Bg7 6.d4 d6 

White to move

7.Nd5

7.Nf3 White could drive the queen back with 7...Qh5 8.h4 h6 9.Kg1 Qg6.

7...Kd8 8.Be2 Nc6 9.e5

Both kings are in the center

9...Nge7 10.Nc3

This retreat gives up valuable time

10.Nxe7 Nxe7 11.Nf3 Qh5 12.h4.

10...Nf5

I think that Black has a clear advantage. White lacks compensation for the sacrificed pawn.

11.Nf3 Qh6 12.Ne4 f6

White to move

13.exf6

13.e6 is interesting 13...Nce7 14.d5 c6.

13...Bxf6 14.g4

Is this move a simple error that loses two more pawns, or is it a clever sacrifice that releases White's pieces from their immobility?

14.Nxf6 Ng3+ (14...Qxf6 is simpler 15.c3) 15.Kg1 Nxe2+ 16.Qxe2 Qxf6 and White has little to show for the sacrificed pawn.

14...Nfxd4 15.Kg2

15.Nxd4? Qh3+ 16.Kf2 Bxd4+ with a strong attack for Black.

15...Bxg4 16.h4

16.Nxd4? Qh3+ 17.Kf2 Bxd4+ and Black's attack must be decisive.

16...Bxf3+ 17.Bxf3 Nxf3 18.Qxf3 Ne5 19.Qb3

Black to move

Threatening the b7 pawn and also Qe6.

19...Qg6

19...b6 20.Qe6 Rf8 21.hxg5 and White gets a good game.

20.Qxb7 Rc8 21.Bd2

White is prepared to bring his queenside rook into play, but the vulnerability of his king is significant.

21.h5 was worth considering 21...Qf5 22.Nxf6 Qxf6 23.Bd2.

21...gxh4+! 22.Kf1 Rg8

White to move

23.Nxd6!

Defending the crucial g2 square and also opening the Black king to attack. McDonnell is able to generate counterplay. However, as Black's king eventually finds security, White's decisive weaknesses on the kingside prove fatal.

23...cxd6 24.Ba5+ Ke8 25.Qxc8+

White has recovered all of the sacrificed material.

25...Kf7 26.Qb7+ Be7 27.Qd5+ Kf8

White to move

28.Rd1

28.Qa8+ does not solve White's problems. 28...Kg7 29.Qd5 f3 30.Rh2 Kh8.

28...f3 29.Rd2

29.Ke1 Qg2

29...h3 30.Qa8+ Kg7 31.Qxa7

Black to move

31...Qg2+!!

La Bourdonnais had to be certain that his king would find security from the checks. The queen sacrifice is temporary, and in fact nets a rook. But the bishop is sacrificed by this move, leaving Black's king exposed.

32.Rxg2+ fxg2+ 33.Kg1 Nf3+! 

33...Kf7 34.Qf2+ Bf6 35.Rh2 Ng4 36.Qf4 and White appears to hold.

34.Kf2 gxh1Q 35.Qxe7+ Kh6

White to move

36.Qxd6+

36.Bd2+ fails 36...Ng5

     36...Nxd2? seems to offer White a draw. 37.Qh4+ Kg7 38.Qg5+ Kf8 39.Qf6+ Ke8 40.Qe6+

37.Qf6+ Kh5 and White has run out of checks.

36...Kh5 37.Qd5+ Rg5 38.Qf7+ Kg4 39.Qc4+

Black to move

39...Nd4! 40.Qxd4+ Kh5 41.Bb6 Qh2+ 42.Ke1 Re5+ 43.Kd1 Qe2+ 44.Kc1

Black to move

44...Qe1+ 45.Qd1+ Qxd1+ 46.Kxd1 h2 0–1

Although La Bourdonnais reached a clear advantage from the opening, McDonnell found play for his pieces and gave us an exciting game. La Bourdonnais's belief in the power of his pawns guided his intuition. Or, perhaps, he demonstrated tremendous powers of calculation when the White queen started her assault.


08 September 2014

McDonnell's Cavalry

McDonnell -- La Bourdonnais 1834

In the twenty-first game of their first match, Louis-Charles Mahé de La Bourdonnais castled queenside and launched a kingside assault with pawns and heavy pieces. Alexander McDonnell responded with a thrust of his a-pawn and fine piece play in the center. La Bourdonnais, playing White, genereated clear checkmate threats, but McDonnell parried these. His a-pawn and knights proved stronger than the French player's heavy pieces.

I am annotating all of the games of this match without reference to engine evaluations. My series on this match began with "Three Fighting Draws". Game 20 is discussed in "Materialism".

De Labourdonnais,Louis Charles Mahe -- McDonnell,Alexander [C24]
London m1 London (21), 1834

1.e4 e5 2.Bc4 Bc5 3.Qe2 Nf6 4.d3 Nc6 5.c3

This move is an improvement over game 19 (see "After a Long Drought ...").

5...Ne7 6.f4

LaBourdonnais opts for some sort of deferred King's Gambit. As there are no other games in the database with this position, the statistics are 100% in favor of Black.

6...exf4 7.d4 Bb6 8.Bxf4

Black to move

White has a strong center, and yet I'm tempted to recall a rule that Emanuel Lasker would lay down sixty years after this game: "bring out your knights before developing the bishops" (see "Lasker's Rules").

8...d6 9.Bd3

Is the e4 pawn threatened somehow?

I like 9.Nf3.

9...Ng6 10.Be3

White occupies more space on the chessboard. On the other hand, Black's pieces do not lack mobility. The knights are well placed on the kingside. White's central pawns are somewhat offset by the half-open f-file. White's king could prove to be vulnerable on g1.

10.Bg5 is quickly refuted. 10...h6 11.Be3.

10...0–0 11.h3 

Black had control of g4. White challenges this domination. However, contesting this square has the consequence of creating vulnerabilities on the dark squares.

11.Nf3 might have been better. 11...Bg4 12.0–0.

11...Re8 12.Nd2 Qe7 

White to move

Now Black has three attackers on e4, which outnumber the two defenders. But, with the Black queen in front of the rook, the pawn remains safe for now. Minor pieces defend a pawn attacked by heavy pieces. Nf6-d5-f4 could be a threat.

13.0–0–0 c5

McDonnell disrupts White's center.

13...Nd5 does not seem as good. 14.exd5 Qxe3 15.Qxe3 Rxe3 16.Bxg6 hxg6 and the game seems equal.

14.Kb1 cxd4 15.cxd4 a5! 

Both players thrust their pawns at the the enemy monarch, but Black's piece play in the center will prevail.

16.Ngf3 Bd7 17.g4 h6 18.Rdg1

White's plan is clear.

18...a4

White to move

19.g5?

19.a3 would prevent the Black pawn occupying this square.
19.Nc4 also guards a3 as well as attacking the dark-squared bishop. 19...Ba5.

Perhaps La Bourdonnais underestmated the power of a Black pawn ensconced on a3. Or, perhaps, he underestimated Black's tatical resources for bringing other pieces to bear on the White king. With Black's knights in front of their king, it is not obvious that they will play a decisive role in the attack on the White king.

19...hxg5 20.Bxg5 a3 21.b3

21.Nc4 may have been worth considering.

21...Bc6 22.Rg4 Ba5 23.h4 Bxd2 24.Nxd2

Black to move 

24...Ra5! 25.h5 Rxg5

Black seeks to eliminate both White bishops, after which the White king will be defenseless. McDonnell's play in this game merits study.

26.Rxg5 Nf4 27.Qf3 Nxd3

White to move

28.d5

28.Qxd3 merits attention 28...Nxe4 and 29.Rgg1 seems best.
   If 29.d5, then 29...Nxd2+ 30.Qxd2 Qe4+ with a decisive gain of material for Black.
   If 29.Rg4, then 29...Nf2 is unpleasant.
Play might continue 29...Nf2 30.Qg3 Be4+ 31.Ka1
   (31.Nxe4 loses quickly 31...Qxe4+ 32.Ka1 Qxd4+ 33.Kb1 Qb2#)
31...Qf6 and Black seems better.

28...Nxd5!

This move appears decisive.

29.Rhg1

29.exd5 fails smply to 29...Qxg5.
29.Rxd5 looked good to me at first, but Black seems to have a decisive attack after 29...Bxd5 30.exd5 Qe5 31.Nc4 Qd4 32.Rf1 f6.

29...Nc3+ 30.Ka1

30.Kc2 is an interesting effort 30...Nxe4 31.Rxg7+ Kh8 32.Qf5 Nb4+ 33.Kc1 Nf6 and the threat of Qe1+ with checkmate to follow.

30...Bxe4 31.Rxg7+ Kh8 32.Qg3

White threatens checkmate.

Black to move

32...Bg6

But Black's checkmate threat appears more serious.

33.hxg6

Can White save the game? 33.Rxg6 Qe1+ 34.Rxe1 Rxe1+ 35.Qxe1 Nxe1 ends as in the game.

33...Qe1+ 34.Rxe1 Rxe1+ 35.Qxe1 Nxe1 36.Rh7+ Kg8 37.gxf7+ Kxh7 38.f8N+ Kh6 39.Nb1 Nc2# 0–1

This game belongs on the list of best games from the first match. I think that it is McDonnell's best game so far. Although La Bourdonnais made a few errors, his play was not substandard.

See "La Bourdonnais's Infantry" for the next game.

03 September 2014

Back to School

Elementary Instruction

School has started for most young children in the United States. Soon, the scholastic chess season will be upon us. Parents, coaches, and players need to stress elementary skills until these become routine. This position from a recent online blitz game illustrates some of these skills.

Black to move

Black has an easy win. First, exchange rooks. Then seize the opposition. Then, use the opposition to perform an outflanking maneuver that gains control of one of the key squares: e2, f2, g2.

Playing blitz, I promoted my pawn in eight seconds from this position. Young players should practice until they can easily perform the correct moves with no more than five seconds per move.

63...Rxh2 64.Kxh2 Kf5 65.Kg1!

White attempts to make trouble for Black.

65...Kf4 66.Kf2

White has the opposition, but Black was prepared with a reserve tempo.

66...f5

Now, Black has the opposition.

67.Kg2 Ke3

Black executes an outflanking maneuver.

68.Kf1 Kf3 69.Kg1 f4 70.Kf1

Black to move

All chess players should memorize this basic position. Black wins no matter who is on move.

70...Kg3 71.Kg1 f3

This position (another than should be committed to memory) is a win for Black because it is White's turn.

72.Kf1 f2 73.Ke2 Kg2

Black finally occupies a key square. The pawn will promote.

74.Ke3 f1Q 0-1

Beginning players should learn the checkmate process from here.



31 August 2014

Materialism

McDonnell -- La Bourdonnais 1834

In game twenty of their first match, Alexander McDonnell sacrificed development for material gain. Louis-Charles Mahé de La Bourdonnais took advantage of this error to launch a decisive attack against White's vulnerable king. McDonnell (1798-1835) was the top player in England in the 1830s. La Bourdonnais (1795-1840) had been France's strongest player for a decade. They met for the match at the Westminster Chess Club in London.

Chess Skills has an ongoing series featuring all of the games in the first match. The series begins with "Three Fighting Draws". My comments on game 19 are in "After a Long Drought ...". My annotations on these games are an element in my own chess training. I am not using chess engines to check my analysis, and make only very limited reference to the work of other commentators.


McDonnell,Alexander -- De Labourdonnais,Louis Charles Mahe [C33]
London m1 London (20), 1834

1.e4 e5 2.f4 exf4 3.Bc4 Qh4+ 4.Kf1 d6 5.d4 Bg4

5...g5 was La Bourdonnais' choice in other games.

6.Qd3

I prefer 6.Nf3.

6...Nc6

White to move

7.Bxf7+?!

Employing a tactic that appears in some of the oldest chess books, McDonnell seizes the opportunity to win a pawn or two.

7.Nf3 might still be worth playing.

7...Kxf7 8.Qb3+ Kg6 9.Qxb7 Nxd4!

Offering the rook may have been a surprising move to the British player.

9...Rc8 10.Qxc6 with a one pawn advantage for White.

10.Qxa8 Nf6

White to move

White has won the exchange, but most of Black's pieces are in play.

11.Na3 f3 12.g3

12.Nxf3 Bxf3 13.gxf3 Qh3+.

12...Bh3+ 13.Ke1

13.Nxh3? Qxh3+ 14.Ke1 Qg2.
13.Kf2 Ng4+ 14.Ke1 f2+.

13...Qg4 14.Be3 d5 15.Qxa7

15.Bxd4 loses the queen. 15...Bb4+ 16.c3 Rxa8.

15...Nc6 16.Qxc7 d4

White to move

17.Bd2

17.Nxh3 does not seem better 17...dxe3 18.Nf4+ Kh6 19.Qxc6 f2+ 20.Kf1 Qf3.
17.Bf2 may hold 17...Qxe4+ 18.Kd1.

17...Qxe4+ 18.Kd1 f2 19.Nxh3 Qf3+ 20.Kc1 Qxh1+ 0–1

McDonnell will win the next game.

26 August 2014

After a Long Drought ...

McDonnell Wins!

McDonnell -- La Bourdonnais 1834

Down eleven wins to two, Alexander McDonnell scored his third win in the match in game 19. McDonnell (1798-1835) agreed to play a match of twenty-one games, draws not counting, against Louis-Charles Mahé de La Bourdonnais (1795-1840), the undisputed champion of France (and presumably of Europe). The match, the first of six between these two contestants, was played at the Westminister Chess Club in London. William Greenwood Walker, the club secretary, recorded the games as they were played.

I am going through all of the games in this match, annotating them for this blog. I am not checking my analysis with a chess engine, so errors should be expected. It is my belief that the games between these two players are a rich source of instructive positions for my teaching of youth players, and also offer plenty of material of value to an A Class player seeking to improve his skill. My peak USCF rating of 1982 was achieved two years ago, and is currently slightly more than 100 below that. I will rise again. When I do, I will credit my teachers McDonnell and La Bourdonnais.

My series on this match begins with "Three Fighting Draws". I discuss game 18 in "Attack and Counterattack".

De Labourdonnais,Louis Charles Mahe -- McDonnell,Alexander [C23]
London m1 London (19), 1834

1.e4 e5 2.Bc4 Bc5 3.Qe2 d6 4.d3 Nf6 5.h3

5.Nf3 seems better 5...Bg4?! 6.h3

5...Nc6 6.c3

Black to move

6...Ne7 

The knight heads to g6, where it asserts influence over f4. This move also prepares c7-c6 and d6-d5.

6...Be6 was played in the two other games that reached this position. Those games were among players whose rating place them in the weak expert category (or Candidate Master). Which move is best? The respective rating of the players does not answer this question. But, it does raise a question: If McDonnell and La Bourdonnais had chess ratings, how would these compare to today's players?

They were the best in their day, but they did not benefit from the established theory that is now the common possession even of most average club players. Rather, their match became one of the important foundations of that theory. Edo Historical Chess Ratings puts McDonnell at a little over 2500 and La Bourdonnais in the mid-2600s.

7.Bb3

A prophylactic retreat.

7...Ng6 8.g3

I don't like this move, and prefer 8.Nf3. Play might continue8...Nf4 9.Bxf4 exf4 10.d4 Bb6 with equal chances for both sides.

8...c6 9.f4?! exf4 10.gxf4

10.d4 Bb6 11.Bxf4
10.Bxf4

10...Bxg1!

McDonnell gets a clear adavantage for the first time in many games.

11.Rxg1 Bxh3 12.f5 Ne5

White to move

13.Rg3

13.Rxg7 seems more active 13...Bg4 14.Qe3 Nf3+ 15.Kf2 Bh5
(15...Rf8 16.Nd2)
16.Nd2 Nxd2
(16...Ng4+ 17.Rxg4 Bxg4 18.Nxf3 Bxf3 19.Qxf3 White is better)
17.Bxd2 Ng4+ 18.Rxg4 Bxg4.

13.d4 is not an improvement 13...Bg4
(13...Neg4 14.Rh1)
14.Qe3 Nf3+ 15.Kf2 Nxg1 16.Kxg1 Qe7 with clear superiority for Black.

13...Bg4 14.Qg2 h5 15.d4 Ned7 16.Bg5 Qb6 17.Nd2 0–0 18.Bf4

18.Nc4 Qc7 19.Ne3

18...d5 19.e5 Rfe8 20.Be3 [20.Nf3 Bxf3 21.Qxf3 Ne4 22.Rh3] 20...h4 21.Rxg4 Nxg4 22.Qxg4

Black to move

22...Nxe5! 23.dxe5 Qxe3+ 24.Kd1 Rxe5

Black has a technical win.

25.Kc2 Qg3

25...Qh6 26.Rg1 Rae8 White's minor pieces seem tied down.

26.Qd4

Black to move

26...Qe3

26...Rxf5 seems possible. 27.Rg1 Qe5 28.Qxh4 Rh5

27.Qxh4 Qh6 28.Qxh6 gxh6 29.Rf1 f6 30.c4

Perhaps White can play on with 30.Kd1 Rae8 31.Bc2 Kg7 32.Nf3 Re3 33.Nd4 h5 34.Ne6+ Kf7

30...Kf7 31.cxd5 cxd5

Black has two passed pawns.

32.Kd3 Rg8 

White to move

The rook occupies an open file, but there are dangers along the diagonal.

33.Rf4

With the idea to play 34.Ne4

33...Ke7

Stepping out of danger.

34.Nf3

34.Ne4?? dxe4+

34...Rg3 35.Kd4 Kd6 36.Bd1

36.Nxe5?? fxe5#

36...b5 37.b4 a6 38.a4 h5 39.axb5 axb5

White to move

White is nearly in zugzwang. The bishop is the only piece that can move. When was this concept first articulated by chess writers?

40.Bc2

40.Nh4 Ree3 41.Bc2 (41.Bxh5 Rd3#) 41...Re2 42.Bb1 Rd2+ 43.Bd3 Rdxd3#.

40...Re2 41.Bd3 Rb2 42.Ke3 Rg4

Black forces White's rook off the board, rendering the b-pawn vulnerable.

43.Nd4 Rxf4 44.Kxf4 Rxb4 45.Ke3 Kc5 46.Ne6+ Kb6 47.Nf4

Black to move

47...Rxf4!

McDonnell demonstrates his mastery of endgame principles. The bishop cannot stop three passed pawns.

48.Kxf4 Kc5 49.Be2 h4 50.Kg4 b4 51.Kxh4 Kd4 52.Kg3 b3 53.Bd1 b2 54.Bc2 Ke3 0–1

McDonnell's technique converting the advantage is worthy of emulation.

In game 20, McDonnell would lose quickly after chasing a material advantage (see "Materialism").