Friday, July 9, 2010

Giant Slaying (part 2): "Strand" and Deliver

My fourth major tournament in chess was the Elk Club Tournament in Denver Colorado. I had been playing chess seriously for a little over a year now and my absorption in the game was in full swing. Very little else interested me at this time and I was quite happy to be infected with this new viral addiction. This particular event was a small four round, two day tournament with three sections: The Open (any rating), The Premier (1800 or less) and the Reserve (1400 or less). Although my rating was only in the low 1100's I decided to play up in the Premier section for the experience of better players while still maintaining a shot at first prize.

The first day of the tournament was a disaster. I lost both games! and with it almost no chance at the top prizes or any prize for that matter! I was a little down but not out and on the second day I was out for blood and determined to have a better showing. My first opponent that day was a B-class player who held a rating over 500 points above me! Like I said, I was out for blood...

White: D. Thomas Moniz (1187)
Black: Gene Strandberg (1717)

Elk Club Tournament
Denver, CO
Time Controls: 2 hours/40 moves; 1 hour SD

Opening: D10 Slav Defense

1.d4 d5 2.c4 c6 3.Nc3 Nf6 4.Bg5!? A rare continuation in this line and for good reason. Modern theory suggests that Black gets a nice game after 4...dxc4. More common here is both 4.Nf3 and 4.e3. Black is already equal if not slightly better. 

4...Nbd7= Strandberg opts too for a quiet continuation rarely seen. Black equalizes easily with 4...dxc4 but perhaps he was already feeling somewhat confident in outclassing me by over 500 points. Now things are level once again. 

5.Nf3 h6 Again Strandberg deviates from the norm. 5...e6 brings us back to well trodden waters in this line while 5...dxc4 seems to give Black a comfortable game. 

6.Bh4 g5!?

Now it's clear that Black is playing for the win. The obvious downside is that he is loosening up the kingside should he opt to castle there. Strandberg was probably feeling that he could just muscle this lower rated player into submission. He soon finds out this will not be so easy. 

7.Bg3 Bg7 8.e3 dxc4 Usually Black waits for White to develop the Bishop before he captures here to make White spend an extra tempo on the recapture but Strandberg seemed to be in a generous if not reckless mood that day. i.e. 8...O-O 9.Bd3 cxd4 10.Bxd4, etc. 

9.Bxc4 b5 10.Bb3 I wanted to put pressure on the f7 square but Black can easily parry this with ...e6 where White will usually jump to c2 so perhaps 10.Bd3 is more accurate. From the d3 square White also attacks all the weak light squares on Black's kingside. 


Trying to shore up his hold on the center. The Knight can now come to c4 or d5 if needed but the timing on this maneuver is bad as White can now win a pawn with 11.Ne5 i.e. 11...O-O 12.Nxc6; or 11...Nc4 12.Nxc4 bxc4 13.Bxc4, etc. 

11.Rc1 Putting indirect pressure on the backward c6 pawn. As mentioned above White has better in 11.Ne5 but the text is strong as well. 


Strandberg's aggressiveness and total disregard for development and King safety will now come at a price. 11...O-O is probably best.
So it's White to move. What would you play here?

Here's a picture of one of my favorite beaches (Sandy Beach) in Hawaii to hide the answer while you think. "Sandy's" as it is usually called is about a ten minute drive from where I grew up. That's Koko Head Crater in the background by the way. A dormant cinder cone of the last active volcano on Oahu about 10,000 years ago! You can click on the picture to enlarge it.

Sandy Beach

Here I played the lackluster but still decent 12.Ne5 but if you found 12.Nxb5! you're on your way to becoming a Grandmaster. Let's look at some variations. If Black plays either 12...O-O (best), 12...Nbd5 or 12...Nfd5 White plays 13.Rxc6 with a big advantage. If Black takes the Knight with 12...cxb5? then 13.Bc7 follows and play may continue with 13...Qd7 14.Ne5! Qf5 15.Bxb6 (On 15.Bxf7+ Kf8 16.Bg6! (less accurate is 16.Rc5 Qe4) Qe6 17.Rc6 Qd5 18.e4! Nxe4 19.Rxb6 with a big advantage)

12...Nc4? going from bad to worse. His threat of course if ...Nxb2 attacking the Queen but this is just a phantom as White has a few ways to deal with it. I in consistent fashion choose second best again with

13.Nxc4 Missing the tactical 13.Nxc6 Qb6 14.Nxb5!! Qxb5 (14...Qxc6 15.Nc7+, etc.) 15.Rxc4 with a big advantage. 

13...bxc4 14.Bxc4 Qb6 15.Qc2 Ba6 16.Be2 I thought I needed to play this in order to castle because after 16.Bxa6 Qxa6 the Black Queen eyes the f1-square. However White can castle immediately if he wants to! i.e. 16.O-O! Bxc4 17.Na4 Qb7 18.Qxc4, etc. 

16...O-O 17.O-O Rac8 18.Na4 Qa7 19.Nc5 White is up a pawn with the superior position.

19...Bb5! 20.Rfe1 Rfd8 21.Be5 Nd5?! Perhaps heading to b4 for a hollow threat against my Queen or maybe just a centralizing move. Better was 21...Nd7 to challenge my Knight. 

22.Bxg7 Removing the only piece protecting the Black King at the moment. Interesting was 22.Bg4! Ra8 23.Be6!! Nf6 (23...fxe6?? 24.Qg6, etc.) 24.a4 Ba6 25.Nxa6 Qxa6 26.Bxf6 exf6 (26...Bxf6? 27.Qg6+!) 27.Bf5 and it's just a technical win from here. 

22...Kxg7 23.a3 Nc7?

A seemingly innocuous move other than the fact that the Black King is virtually unprotected save a few pawns at the moment. Better for Black is 23...Bxe2 24.Rxe2 Nf6 but things still are not well for him. 
So what would you play here as White?

Here's another picture to hide the answer: (click on it to enlarge)

It's an aerial view of Hawaii Kai and Kokohead Crater on the island of Oahu. The white arrow is Sandy Beach and the yellow arrow is where I grew up. Pretty cool huh?! That big bay area to the left of Sandy's is Hanauma Bay, an awesome place for snorkeling as a protective reef keeps out the really big sea creatures. There is no fishing or poaching allowed so ocean life withing the bay are very tame -some will eat right from your hand!

OK if you found 24.Bh5! give yourself full credit. The Bishop here will play a powerful roll in the attack against the Black King. At the time I hadn't yet calculated much of anything other than the play against the f7 square and that this Bishop was worth keeping because most of my pawns were on dark squares. 

24...a4 It's hard to find useful moves for Black already. He wants to keep me from playing a4 but no doubt doesn't see the danger lurking ahead on the kingside (I hadn't yet even seen the full potential of the position!) or he would of played something like 24...Rf8 and meet 25.Qf5 with ...e6 where it's not so clear how to proceed... maybe 26.Qe5+ but then comes ...f6 so it's not clear. 

25.Qe4 Attacking the e-pawn and moving my Queen closer to the prize but I still hadn't come up with anything concrete. My instincts told me that there had to be something here as all of Black's forces are on the other wing with no quick way back. In the post game analysis some master pointed out 25.Qf5! which I rejected during the game because after ...Rf8 I thought Black was holding but then the master points out 25...Rf8 26.Bxf7! Rxf7 27.Qxc8. I guess when you're 1200 rated you don't see stuff like that... 


Protecting the e-pawn with aspirations of landing on f6 attacking both my Queen and Bishop. Black can also hope to play ...e6 and then ...Qe2 at some point to bring in some help for his King under siege. The silicon beast Firebird finds 25...Ne8 as preferable for some reason. 

So it's White to move. What would you play?

Spain's football (soccer) logo for their national team in both home and away jersey colors with the brand new gold star for their fine win of this years World Cup over Holland (the Netherlands) in the finals. It was the first time Spain has ever gotten to the finals in a World Cup!

OK full credit for 26.Ne6+! I was very proud to of found this move. I calculated getting at least three pawns for the piece and a strong attack. I couldn't calculate a mate but decided to go for it anyway as the attack looked strong enough. Firebird finds the even stronger 26.Bxf7! and gives 26...Rd6 (26...Kxf7? 27.Qh7+ Kf8 28.Qxh6+, etc.) 27.Qe5+ Kxf7 (27...Nf6 28.Qf5 Kxf7 29.Qxc8, etc) and (27...Rf6 28.Bxd5! Re8 (28...cxd5 29.Ne6+) 29.Ne6+ Kh8 30.Bxc6, etc.) 28.Qf5+ Rf6 29.Qxc8 Yes maybe stronger but I like my move better. Black finds the best move now with 

26...Kg8! On 26...fxe6? comes 27.Qg6+ Kh8 28.Qxh6+ Kg8 29.Qxg5+ Kh8 30.Qh6+ Kg8 31.Qg5+ Kh8 32.Bf7 Bd3 with a forced mate in 5 according to Firebird.
Here's the position in the above variation after 32.Bd3.

*position in the above variation after 32.Bd3

White to play with a mate in 5. Try and find it.

More World Cup action from yesterdays finals to hide the answer.

In the 28th minute of the game, running to the ball Spain midfielder Xabi Alonso is stopped in his tracks by a high kung-fu kick to the chest from Holland midfielder Nigel de Jong. Yes they have studs on those shoes! The blow not only stopped the Spaniard's forward progress but put him straight down to the pitch writhing in agony. de Jong was given a yellow card for the blow but should of been given the red right there.

OK here's the solution: 33.e4! Nf6 (
33...Bxe4 is mate in 3; and 33...Kh7 is mate in 2) 34.Qh6+ Nh7 35.Bg6 Kg8 36.Qxh7+ Kf8 37.Qf7#

Now back to the actual game:

27.Nxd8 Rxd8 28.Qf3 Rf8

Now it looks like Black is consolidating his position and I remember thinking I had to keep up the attack and get at his King so here I played 29.h4! prying open the kingside further. 

29...f5 30.hxg5 hxg5 31.Rc5! Threatening Rxd5! cxd5 Qxd5+ winning the Bishop. This was not an easy decision for me as I had to calculate what to do on 31...g4 but in the end saw that I would be OK after 32.Qg3. Firebird finds 32.Bxg4! fxg4 33.Qxg4+ Kf7 34.Qh5+ Ke6 35.Rxb5! cxb5 36.Qe5+ Kf7 37.Qxd5+, etc. but of course this is almost impossible to find OTB when you're a 1200 rated player!

31...e6?! Giving extra support to his Knight and f-pawn and opening up a lane for his Queen to come over to the kingside but this only makes matters worse for him. Better was 31...Qa5 32.Rec1 e6.

32.e4! forcing the Knight off this post and opening up lanes for my Rooks. I'm also opening up the Black kingside further. 

32...fxe4 33.Qxe4 Nf4? But what else? 33...Rf6 runs into 34.Bg4 Qf7 35.Bxe6 Rxe6 36.Qxe6 Qxe6 37.Rxe6 and Black will not be able to hold the position. 

34.Rxg5+ And here Black resigned in lieu of 34...Kh8 35.Qe5+ Kh7 36.Re4, etc.
final position

This by far was my biggest victory in chess up to this point and needless to say I was pretty elated with the win!

Mousetrap Musings (part 1): A "Minor" affair

I've played many games over a beer or five at my local neighborhood pub, the Mousetrap.This blog, "Mousetrap Musings" will be various games from those denizen encounters.

In this game I play one of my regulars whom I've had dozens of games with. This particular game is our seventh game in an ongoing open match. At the time of this game our score stood at 5-1 in my favor.

White: Sherman Minor (unr)
Black: D. Thomas Moniz (1520)

Mousetrap Bar & Grill
Indianapolis, IN
(no time controls)

Opening: B20 Sicilian Najdorf

1.e4 c5 2.Bc4 e6 3.Nf3 d6 4.d4cxd4 5.Nxd4 Nf6 6.Bg5!? A surprise and not a common continuation in this line. More common here is 6.Nc3. My opponent seeks to use tactics to defend the e-pawn but this is suspect. 

6...Be7= Firebird suggests 6...h6 here and now7.Bxf6 (7.Bh4?! g5! 8.Bg3 Nxe4 winning the e-pawn with advantage.) 7...Qxf6= as Black's best continuation but the text is OK too. 

7.Nc3 a6 8.Qe2 O-O Interesting is 8...Nxe4!? 9.Nxe4 (another try is 9.Bxe7 Nxc3 10.Bxd8 Nxe2 11.Bb6 Nxd4 12.Bxd4 b5 13.Bd3 Bb7 with a material advantage for Black but White may have real compensation in the bishop pair.) 9...Bxg5 10.Nxe6! fxe6 11.Qh5+ g6 12.Qxg5 d5 13.Qxd8+ Kxd8 14.Ng5 dxc4 15.Nf7+ Ke7 16.Nxh8 Nc6 17.Nxg6+ hxg6 with about equal chances but Whites game looks easier. (see diagram)

*after 17...hxg6 in the variation above.

9.h4!? Minor true to form wastes no time in spearheading his attack but this is too reckless. Better and more sensible are 9.Bd3; 9.O-O-O; or 9.Rd1. Black is already equal if not better here. 

9...b5 10.Bd3 Bb7 11.g4?!

after 11.g4?!

Whites attack is very ambitious indeed! At first glance it would seem Black's kingside will soon be under siege from a wall of enemy pawns but this is only an illusion. Cool heads will prevail and it is Black's counter-thrust that will be felt. 

11...Qb6?! Attacking the undefended Knight but this is easily parried with tempo. Instead 11...b4! keeps a good advantage for Black. i.e. 12.Nd1 Nbd7 13.f3 Qb6 14.Nb3 a5, etc. 

12.Qe3 Better was 12.Be3 with a discovered attack on the Black Queen. White also frees the g5 square for the pawn to attack. 

12...Nxg4 I was a little concerned here about taking this pawn and opening up a line on my King but ultimately felt I could defend. 

13.Qf4 Bxg5 14.Qxg4? Capturing the Bishop was paramount. i.e. 14.hxg5 Ne5 (The other capture, 14...Qxd4?! runs into a plethora of complications after 15.Qxg4 b4 (15...Nd7 16.Rxh7! Kxh7 17.e5+ Qxd3 18.cxd3 Nxe5 looks a little better for White) 16.O-O-O!! (16.Nd1 Nd7 is a little better for Black) 16...g6! (16...bxc3? 17.e5 Qxg4 18.Bxh7+ is a forced perpetual check) 17.Ne2 looks equal. Now Black retains an excellent defender for his kingside and all but squashes White's counterplay. I must admit from the position below after 14.Qxg4 it's not easy to see concretely Black's huge advantage but according to Firebird it's there.

after 14.Qxg4?

14...Bf6 Worse is 14...Qxd4?! 15.hxg5 b4 16.O-O-O!! Qxf2 (16...bxc3 17.e5 Qxg4 18.Bxh7+ with a perpetual) 17.Rd2 Qd4 18.e5 and White slips away with a perpetual. 

15.Nf3 Nd7 16.Qg2 White has plans of castling queenside and so drops back to protect the f-pawn but this is too slow. Better was 16.Rg1 with pressure on the Black King but this even this is going nowhere with proper play by Black. 

16...Rac8 17.h5

after 17.h5

17...h6 I actually did consider 17...Rxc3! 18.bxc3 Bxc3+ 19.Ke2 Bxa1 (Fritz finds 19...f5! 20Ng5 (20.exf5? Ne5 21.Rab1 Bxf3+ 22.Qxf3 Nxf3 23.Kxf3 Qd4 with a crushing attack!) 20...Bxa1 21.Rxa1 fxe4 22.Bxe4 Bxe4 23.Nxe4 and Black is two pawns up with the better pawn structure) ...but first wanted to stop the h-pawn from advancing further as I thought 20.h6 would give White strong counterplay. This is silly because Black always has 20...Bc3 or ...Bf6. 

18.Ne2?! But what else does White have? 18.Nd2 runs into ...d5 threatening to open up the long diagonal with devastating effect. So it seems White is without any useful moves. 

18...Bxb2 19.Rb1 Qa5+ 20.Kf1 Bf6 21.Rh3 Probably with the idea of loading up on the g-file against my King but this will be way too slow. 

21...d5 22.exd5 Bxd5 The Black bishop-pair is completely dominating.

after 22...Bxd5

23.Nc3? A simple blunder in a almost hopeless situation. On 23.Qg3 Black simply plays ...Qxa2 24.Re1 Nc5 and White is helpless. 

23...Rxc3 24.Qg3 Qc7 Black has an easier win after 24...Nc5 or ...Qxa2 but I felt my advantage was big enough to win with the Queens off and didn't want to worry about White swindling his way into any checkmating attacks. 

25.Qg4 White knows he is far behind and wisely opts to keep the Queens on to at least give him a shot at a lethal counterstroke should I falter. 

25...Ne5 26.Nxe5 Qxe5 27.Rg3 Bc4 28.Bxc4 Rxc4 29.Qd1 Rd8 30.Qg4?? Another simple oversight but there was really nothing else anyway. Now the end comes quick. 

30...Rxg4 31.Rxg4 Bg5 32.Re1 Qd5 33.Rg1 Qxa2 Instead 33...Qc4+ is mate in 9 which of course Firebird finds. 

34.Ke2 Qxc2+ 35.Kf3 Rd2 36.Rg2 Qf5+ 37.Kg3 Qf4+ 38.Kh3 Qh4#

final position

Saturday, May 15, 2010

Giant Slaying (part 1): Toe to toe with a GIANT

Here's a game I played a couple of weeks ago against a Serbian IM in a thirty board clock-simul on ICC. If I remember correctly he scored 23 wins, 2 loses and 5 draws. It's my best result against a 2200+ rated player to date.

White: IM Zoran Petronijevic (2405 FIDE)

Black: D. Thomas Moniz (1520 USCF)

Internet Chess Club

Simultaneous Exhibition

C01: French Exchange Variation

1.e4 e6 I used to play the French when first started out but shelved it after I found Fischer and the Sicilian. I've recently started playing it again just for variety.

2.d4 d5 3.exd5 The Exchange French. It must be in fashion these days for White because I see it a lot when playing blitz online.

3...exd5 4.c4 I haven't encountered this line a lot. In fact I can't remember the last time I did. White is allowing me to give him an isolated pawn for more piece mobility and freedom, which may lead to attacking chances for him. Offer declined.

4...Nf6 5.Nc3 Be7 OK it's only move five and I'm already in unfamiliar territory. Not an great start but at least I'm just playing chess now and not trying to remember theory. 

6.Bd3 dxc4 This sort of idea is found in the QGD. In some lines Black captures this pawn as soon as the Bishop develops. I'm not sure if it applies in this position but it felt right.

7.Bxc4 c6N According to my database this is a novelty but probably not anything significant. I'm just trying to control the d5 square.

8.Nge2!? Not sure why he developed the Knight here. Perhaps he want to put it on g3? Maybe in case of Bg4 he can break the pin with f3? 

8...O-O 9.O-O Bf5 Not sure if this is the right place for the Bishop but I wanted to develop it before the Knight comes to d7. Maybe it can help with the defense of my king side if need be. 

10.Ng3 Bg6 11.Bf4 The Bishop looks a little strange here I thought. I was having trouble finding a home for my dark-squared Bishop so why not just trade it off was my rational. 

11...Bd6 12.Be5!? Unexpected. Now if I capture White rids himself of his isolated pawn and after f4 I'm not so comfortable. Also, my plans to develop the Queens Knight to d7 is hampered. 

12...Bc7 13.Re1 Nbd7 14.Bb3 

One of those "mysterious" maneuvering moves that Masters do a lot. I'm not sure why he chose to pull back the Bishop at this moment. Perhaps he saw some sort of tactics going on but I don't see anything.   I was kinda liking my position here. I have no discernible weaknesses however I am a little cramped at the moment. I still need to figure out where to put my Queen though.

14...Re8 15.f4 h6 16.Qf3 OK White if very active now and I'm feeling a little uneasy. Besides being in closer proximity to my King now his Queen eyes the d5-square adding a third attacker to it. 

16...Nb6 To secure d5. Instead 16...Bb6!? was pointed out to me later attacking the pawn and pinning it to the King. I actually considered this during the game but didn't after the King moves away I wasn't sure how to stop White's d-pawn from advancing and I'm still cramped. 

17.h3 I was expecting 17.Rad1 but I suppose White has time for such prophylaxis. 

17...Qd7 I want to play Rad8 but simply forgot that my Queen was guarding my f6 Knight. Now if White captures it I have to take back with the pawn wrecking my King's protection. Later on in post game analysis I found this might of not been so bad. 

18.f5 Bh7 19.Rad1 Nfd5?!

white to move

I was still worried about Bxf6 and was glad to move the Knight away and plus now I'm blockading the d4 pawn. Of course removing a defender from your King is always a little risky when there are enemy forces zeroing in. 

What would you play as White here?

Here's a picture to hide the answer while you think.

J.C. Macneil (left) of Colorado playing blitz on the 16th St. Mall

This is the chess tables on the 16th St. Mall in Denver where it all started for me some fourteen years ago. I took many beatings here and then later on delivered a few myself.

OK back to the game. Here White played the surprising 20.f6?! Sacking a pawn to open up my King. Probably not what you guessed as later analysis shows that after 20.Qg4 White has a strong attack. Even 20.Nxd5 gets full credit.

20...Nxf6 I can refuse the pawn with 20...g6 but didn't feel like suffering through that position. 

21.Bxf6 Rxe1+ An important intermezzo. Otherwise 21...gxf6 22.Nce4! Bxe4 23.Nxe4 is a little uncomfortable. 

22.Rxe1 gxf6 23.Nh5? Amazing! White is trying to be too clever. Now I take over the steering wheel. After the simple 23.Qxf6 White is still in the drivers seat. 

23...Qxd4+ Petronijevic must of simply missed this capture with check else why play Nh5? 

24.Kh1 Be5 I should immediately give back the pawn here by playing something like 24...Bg6 as now White begins to bear down on my King. 

25.Ne4 f5 26.Neg3

Black to move

Now what would you play here? Only one move keeps Black on top.

more action on the 16th St. Mall

OK so after a short think I play the horrible 26...Bxg3? I wanted to relive some of the pressure of the attack and figured that removing some pieces off the board would do the trick but this is not the case. If you guessed 26...f4! then give yourself full credit. After 27.Qg4+ Kf8 28.Nf5 Qxb2 29.Nxh6 Qc3 Black is doing fine. 

27.Nxg3? Reprieve! Another stunner from Petronijevic. After the obvious 27.Qxg3+ Kh8 (27...Kf8?? 28.Rd1! f4 29.Qh4 is a little annoying) 28.Bxf7 f4 (to deflect the Knight away from the g7 square) 29.Nxf4 Qg7 and Black is fighting for a draw.

27...Nd5 I actually considered 27...Qh4 eying the e1 Rook but thought my Queen would be too out of play here after the Rook moves away. This assessment is wrong. The Queen is better placed on h4 to help with the King's protection. 

28.Nxf5 Bxf5 29.Qxf5 Kg7 30.Re4 Qd2? I didn't think taking the meaningless pawn on b2 was a good idea with all that firepower around my King. I wanted to interpose on g5 should White check on g4. However Black is better off staying on the a1-h8 diagonal. Another way to play is 30...Qf6.

31.Rg4+ Kf8 32.Kh2?! Profilaxis. White does better with 32.Qe5 or perhaps 32.Bxd5 but it's hard to fault him when the text lulls me into playing 

32...Qxb2?? losing on the spot. After 32...Re8 bringing the dormant Rook finally into play I can relax a bit. 

33.Bxd5 cxd5 34.Rf4 f6

Ok what would you play here as White?

a quiet chilly night on the 16th Street Mall

If you saw 35.Qe6!! congratulations! It's the only move that holds Whites massive advantage. For instance, 35...Kg7 36.Rg4+ Kh8 37.Qf7 Qe5+ 38.Rg3 f5 39.Qg6 winning. Everything else let's Black back in the game including what my generous opponent played: 

35.Qxd5? Petronijevic must have been really taxed in his other games to lapse into this irresponsible pawn grab. Now I get my Rook involved in the action.

35...Re8 36.Qh5 Re2?! I'm currently up a pawn so I'm trying to drum up some counterplay but this is risky as my King is too exposed. Black should be playing to just hold the position with 36...Qe5. 

37.Qxh6+Ke7 38.Qg7+ Ke6?! Allowing a clever little tactic (39.Ke6!) that fortunately the overburdened Master misses. However Black should be able to draw despite of this. More accurate is 38...Ke8. 

39.Qg8+?! Missing 39.Rxf6!+ Qxf6 40.Qg4+ but Black should still be able to draw here. 

39...Ke7 40.Qg7+ Ke6?! Again the same idea as above. 

41.Qg4?!+ And again missing the above mentioned tactic. 

41...Ke7 42.a4 Maybe 42.Qf3 is better. Now Black has an easier time of drawing. 

42...a5? Which I miss... Now White can play 43.Rf5! The point being that 43...b6? (better is 43...Qd2! 44.Qg7+ Kd8 45.Qxf6+ Kd7 where Black has drawing chances.), is met with 44.Rd5! threatening Rd7+. For instance if Black plays something like 44...Qa2 (no better is 44...Kf8 45.Qg6 Re8 46.Rh5, etc.) play continues with 45.Rd7+ Kf8 46.Qg7+ Ke8 47.Rb7 etc., and White will win. Black avoids this unpleasantness with 42...Qe5. 

43.Re4?! Now it's an easy draw for Black. 

43...Rxe4 44.Qxe4+ Kf7 45.Qd5+ Kg6 46.Qxa5 Qd4 47.Qb5 Qf4+ 48.Kg1 Qe3+ 49.Kf1 Qf4+ 50.Ke2 Qe4+ 51.Kf2 Qf4+ 52.Ke2 Qe4+ 53.Kf2 Qf4+ 54.Ke2 Draw

final position