Sunday, December 27, 2020

CHESS CAMP Dec 28-31 at the Chess Center!


Call 585-442-2430 for Details and to Register 
Dec 23, 28-31 Christmas / New Year Break

Also: Jan 18 Martin Luther King Day
Feb 15-19 Winter Break
Mar 29 - Apr 2 Spring Break

The Chess Center has developed a plan for Chess Camp with Precautions in place.

Camp is available to students age 5-13 years. All skill levels from beginner to advanced are encouraged to attend. Beginners who arrive without any knowledge of the game will become proficient players from their camp experience; advanced players benefit from sharing classes and experience with some of the top scholastic players in the USA.

Because this is our 30th year of offering camps, our counselors are among the most experienced chess teachers found anywhere. We coordinate daily activities and instruction to expand the student's chess skills. Chess is known to teach logic, problem solving, analysis techniques, and will improve study habits. These skills have obvious carry-over benefits to schooling and career. But, the main reason kids come back to our chess camps year after year is because...


Rochester Chess Center is located near Cobbs Hill Park, at 221 Norris Drive. There will be daily outings to the park for seasonal activities (Frisbee, soccer, hiking)... so dress for outdoor action.

You can call for information or to register by calling the Chess Center at 585-442-2430.  Or just show up in the morning to join the chess camp!

Saturday, December 26, 2020

Dr. Rawle Farley Memorial Monday Night League begins Jan 4th

     Hello everyone and happy holidays (however you celebrate).

Just a quick reminder that the latest season of the Dr. Rawle Farley Memorial Monday Night League will begin its Winter League (season XL) on Monday January 4.  Check out the web site for more information at

If you are interested, please call or e-mail to let us know.  Pre-registration is NOT required  — you can simply show up —  but every little bit of advance information helps. 

Otherwise, chess activities continue.  The Chess Center itself was closed Dec. 24 and 25, and it will be closed Jan. 1 but it is open every weekday.  Wednesday’s the Community Chess Club continues to meet, and Saturday tournaments continue as well.

Also, if you know youths who might be interested, the Chess Center is running chess camps next week (Monday through Thursday (Dec. 28-Dec. 31).

For all Chess Center activities, COVID safety protocols remain in place:  masks, social distancing, disinfecting/sanitation, and a request to self-quarantine if you’ve felt ill. 

If you’d like to be removed from e-mail notices, or you wish to change your e-mail address, please let us know.

Stay safe, be well and we look forward to seeing you soon.

    The Rochester Chess Center

Thursday, December 24, 2020

Online Chess Lessons available now on our club's Youtube channel

No tournaments to play in?  Worried about your chess getting rusty?  Enjoy four online chess lessons produced by the Community Chess Club of Rochester this past summer.  In the four lessons we have about 8 hours of FREE chess instruction with some of the highest rated instructors in upstate New York.  If you missed the online Zoom meeting when we did these lectures live online, you now can enjoy the recorded lessons on our club's Youtube channel.

Instructors: Lev Paciorkowski, Clif Kharroubi & Ken McBride

Lesson 1: Rook Endgames

Lesson 2: Pawn Structures

Lesson 3: Chess Misconceptions

Lesson 4: Grandmaster Blunders & Bonus: Lev demonstrates the Knight's Tour

Wednesday, October 28, 2020

David Phelps wins the 2020 Club Championship!


Congratulations to 

David Phelps
The 2020 Community Chess Club
 of Rochester Champion!

Rochester, NY October 28, 2020.  In the Final Round of the 2020 CCCR Championship at the Chess Center, David Phelps and Henry Swing agreed to a draw in an exciting endgame battle.  David won the tournament by tie-breaks with 3.5 points.  Henry Swing took 2nd place.  Ken McBride took 3rd place by tie-breaks with 3 points, and Clif Kharroubi took 4th place.  The U1800 winner was Jamshed Ahmed by tie-breaks with 3 points. The U1500 winner was Nathan Shaffer with 2 points.  The U1200 winner was Richard Warmus with 1.5 points.  The U1000 winner was Robert Fulton with 1 point.  There were 28 club members participating this year's annual club championship.  Congratulations to all the prize winners!  Thanks to everyone who took part in this year's club championship.  Thanks to Ron Lohrman who was the tournament director.  Join us for Awards Night on November 11, 2020 at 7:30pm.  

Round 4 with David Phelps (left) and Henry Swing

David Phelps - 1st place

Henry Swing - 2nd place

2020 CCCR Championship Participants

Clif Kharroubi (right front) won his game against Toby Rizzo

Ken McBride (right) won his game against Eric Piato

Final Standings:

Cross Table:

Click Here for the Photo Gallery

Jamshed Ahmed (right) won his game against TJ Weaver.

Ryan Beh (right) won his game against Don Stubblebine.

Awards Night 
will be held at the Rochester Chess Center 
on Wednesday, Nov. 11th, 2020 at 7:30pm. 
Please join us for the award ceremony.  Cake will be served in skittles room.
The club's regularly scheduled chess games will follow the awards ceremony.

James Attaya

Thursday, October 22, 2020

2020 CCCR Club Championship: Round 3

Wednesday, Oct. 21st was round #3 of the club championship.  The chess action took place at the Chess Center in Rochester, New York.  It was an exciting night and there were plenty of great chess battles on the 64 squares.  The current club champion, Lev Paciorkowski, has withdrawn from the tournament in order to participate for Norms at the 14th Annual SPICE CUP in St. Louis (, Missouri.  This means that the Community Chess Club will have a new champion this year. 

Toby Rizzo (right) won against Peter Craig.

David Phelps (left) won against Ken McBride

Henry Swing (right) won against Don Stubblebine

CCCR member TJ Weaver has provided these games and analysis:

Round 4 will be held next Wednesday, October 28.

Saturday, October 17, 2020

2020 CCCR Club Championship: Round 2

Round 2 was held on Wednesday, October 14, and as usual there was plenty of excitement! We had a turnaround upset on board 2, and at one point I had an objectively lost position on board 1. Let's dive into the games.

Let's start with our game of the week, which was Henry Swing's (1936) win over Clif Kharroubi (2098), overcoming a more than 150 point rating gap.

A lucky escape for Henry to be sure - after having a nearly lost position out of the opening he was still able to keep the game going and ended up winning after Clif's critical blunder on move 50.

In my game against TJ, after being unfamiliar with the opening I came up with a bad plan and found myself in a difficult position. While 9. ... f6!? would have still been OK for black, the exchange sacrifice I played instead was just unsound - I missed a couple key tactical details and also overestimated the long-term weakness of white's king.

Nevertheless, TJ went astray with his reckless kingside expansion, and despite my bad opening I was able to take advantage of my opponent's mistaken strategy beyond move 14.

I have one other game from this week too, which was the board 5 encounter between Ryan and Ken:

A tough long game. Ryan was hanging in there until losing the pawn on a2, when with two outside connected passers Ken was able to bring in the full point.

Here are the full results for this round:

Round 3 will be held next Wednesday, October 21.

Saturday, October 10, 2020

2020 CCCR Club Championship: Round 1

 Round 1 of the 2020 Club Championship was held last Wednesday on 10/07. This year I'll be spotlighting one game from each round (typically an upset) and analyzing it.

Even with many of the boards seeing large rating disparities in round 1, we had at least two very significant upsets, one of which I've gotten the game score for.

The first was Vinnie Basile's (1212) win over Greg Miller (1820), which I have as the game of the week below:

The second upset I know about was Shaffer's draw against Stubblebine, another roughly 600 point rating gap. Here is the notation for that one:

A very back-and-forth struggle, where white won a pawn in the opening, then black won the pawn back, and in the RN vs RB ending black was surely winning most of the way before losing the queenside pawns. In the final position, white is actually winning the king and pawn ending since black's king is held back on the kingside!

On the top boards, the higher rated players generally prevailed, with David Phelps winning as black against David Lusignan on board 4 and Peter Craig winning against Aidan Kharroubi on board 3. Clif Kharroubi won by forfeit on board 2 and I won my game against Arianna Kharroubi.

Below are some of the other games I was able to get the notation for this round - here is Attaya - Rizzo from board 6:

And Lusignan - Phelps from board 4:

Finally, here are the standings after the opening round:

Don't miss round 2 next week!

Friday, October 2, 2020

2020 Club Championship

The 24th Annual Community Chess Club Championship

Starts Wednesday Night, October 7th 2020.  Four Rounds G/80d5.  
One game per week at the Rochester Chess Center.  
Registration is now closed for this event.

Games and updates will be posted for each round.

Wednesday, September 9, 2020

My Games from the 2020 New York State Championship

The 2020 New York State Chess Championship was held online this year from September 5-7 on the Internet Chess Club. With a combination of good opening preparation, tactical awareness and a little luck I managed a clean 6-0 sweep! I've selected a few of my games to analyze.

Let's start with round 2, which was definitely my sloppiest game of the event:

Paciorkowski, Lev (2443) - Ehsani, Yassamin (2095); Round 2

White to move

The opening has gone rather adventurously and my king did not end up finding a secure home. So naturally, I was very relieved in this position to be able to play 19.Qg5 trading the queens. After 19. ... Qxg5 it is difficult to say which recapture is best, but I went with the more ambitious one 20.fxg5!? gaining a tempo to win the b5 pawn: 20. ... Nf5 21.Bxb5 Be6 (D)

White to move

White is up a pawn but the pieces are so badly coordinated that black has pretty good compensation. My advanced kingside pawns have some cramping effect, but they also could turn out to be weaknesses, so this is double-edged. The game continued 22.Ke2 Rac8 23.Bd3 Bb6 24.Rc1 Rxc1 25.Bxc1 Rc8 26.Nf2 and now 26. ... d4! 27.e4 Ne3 (D) upped the stakes even more.

White to move

Black has gotten the so-called "octopus" knight on the third rank, and things do not look so rosy as there is also a threat of ...Rc5-xe5 regaining the pawn. I can play 28.Bxe3, but after 28. ... dxe3 neither 29.Ng4 Bxg4+= nor 29.Nd1? Rc1! -+ are what I want. However, it turns out that white has a surprising idea in this position. 28.Bb2! Preventing Rc5 by attacking d4... 28. ... Bd7 black naturally prepares Re8-xe5 instead. 29.Bb1!? Re8 30.a4! Rxe5 31.Kd3! Now the point of 30.a4 becomes clear: it was necessary to prevent ...Bb5+ in this position. I at first thought white was just winning, because the threat is Bxd4 when the Ne3 is suddenly trapped. I then realized black has an only move, which my opponent found: 31. ... Re6! planning a pin if I take on d4. Things are once again far from clear and after 32.Ba2 Rc6 33.Rc1 Rxc1 34.Bxc1 (D) I actually offered a draw, having just 7 minutes to my opponent's 39 minutes (time control is G/90 + 10).

Black to move

It looks like black has all the cards with a superb knight and lots of weak pawns to attack on the kingside. My engine assures me this is still equal, but during the game I thought black was simply much better. At this point I had an unbelievable stroke of luck: my opponent declined the draw, and then in four moves managed to give himself a lost position! 34. ... Ng2 35.Bd2 Bc7 36.h3 Nf4+? 37.Kxd4! Nxh3+? 38.Nxh3 Bxh3 39.b4! (D)

Black to move

On move 36 something like ...Be6! would have been much stronger, maintaining the tension and freezing my queenside. Now white's active king, 2-1 queenside majority and black's inability to make a passed pawn on the kingside give me a decisive advantage. With 5 minutes left I was able to convert: 39. ... Kg7 40.e5 stopping ...f6 Kf8 41.a5 Bf1 42.Bf4 Ke7 43.Bc4 Bg2 (43. ... Bxc4 44.Kxc4 is winning for white: 44. ... Ke6 45.Kc5 Kf5 46.e6! +-) 44.Bd5 Bf1 45.Kc5 Ba6 46.Kc6 Bb8 47.Bxf7 Bd3 (47. ... Kxf7 48.e6+ Kxe6 49.Bxb8 +-) 48.Bd5 Ba6 49.Bf3 Bc8 50.Bg2 Ba6 51.Bh3 Kd8 52.b5 Bc8 53.Bxc8 Kxc8 54.e6 1-0

Not my best game, but I'll take wins any way I can get them.

After winning my next two games against experts, it turned out that Jason Liang (2403) was the only other player with a perfect score. He had just won with black against GM Vladimir Belous (2635), and GM Timur Gareyev (2692) had drawn with FM Justin Chen (2390). All this meant my round 5 pairing would be black against Liang:

Liang, Jason (2403) - Paciorkowski, Lev (2443); Round 5

1.Nf3 Earlier in the tournament Jason had played 1.e4, but I saw he also has been playing d4 openings recently. 1. ... Nf6 2.c4 g6 3.Nc3 This is a very specific move order that white often chooses to avoid the main lines of the Grunfeld. If black now plays 3. ... d5 4.cxd5 Nxd5, white has lots of options including 5.e4, 5.Qb3, 5.Qa4+ and more recently even 5.h4! I was not very well prepared for any of this, so decided to enter a KID instead. 3. ... Bg7 4.d4 To my eyes this is a curious move order, because now Jason is allowing one of the mainlines of the Grunfeld if I wanted it -- instead 4.e4 would all but force a KID. Anyways, we got to the same position regardless. 4. ... 0-0 5.e4 d6 6.Be2 Na6 7.0-0 e5 8.Be3 Qe7!? (D)

White to move

I rarely play the King's Indian nowadays, and only used it here because of this very specific and unusual idea I wanted to try out. Normally if black chooses to move the queen it goes to e8, but on e7 it has the chief advantages of not blocking the Rf8 and controlling c5. There are some other details, but suffice it to say this is actually the top choice of the modern neural network engines Leela and Stockfish NNUE so it can't be all that bad! Black's top 3 alternatives are Ng4, c6 and Qe8; Qe7!? is the sixth-most common in my database with just 91 games played.

9.Qc2! Jason played this rather quickly, which came as an unpleasant surprise because I think it is the most challenging response, and the main line of NNUE. The idea is to clear d1 for the rook, so now white threatens 10.dxe5 dxe5 11.Nd5 Qd8 12.Rad1 +/-. I cannot play 9. ... c6? on account of the thematic 10.c5! dxc5 11.dxe5 +/-. This means the following transformation is virtually forced: 9. ... exd4 10.Nxd4 Re8 11.f3 c6 12.Bf2 (D) stopping the ...d5 break. At this point I was out of my prep.

Black to move

As a result of Jason's 9th move, we have gotten into an open KID structure. These positions are known today to be simply better for white, and black basically shuffles his pieces around playing for tricks. White's main plan is to start a pawn roller on the kingside: h2-h3, then f3-f4 and g2-g4 to gain more space. I wasn't very comfortable in this position, but in any case the game continued...

12. ... Nc5 13.Rad1 preparing Bg3 to hit d6, so I maneuver a N to e5: 13. ... Nfd7 14.Rfe1 a5 15.Bf1 Ne5 16.Kh1 a4 17.Qd2 Qc7 18.h3 Qa5 (D)

White to move

The first critical moment. Here I was most concerned about 19.f4! Ned7 20.g4!, which gives white a serious plus - it exposes the king but black lacks the piece coordination to properly take advantage of it. Instead white played 19.Nc2? allowing the thematic sacrifice 19. ... Bxh3! 20.Qxd6 (20.gxh3? Nxf3 21.Qxd6 Nxe1 -+ is bad for white; so is 20.f4?! Bg4! 21.fxe5 Bxd1 22.Rxd1 Rxe5! -/+ 23.Qxd6?? Rh5+ 24.Kg1 Be5 -+) 20. ... Bf8 21.Qf6 Bg7 22.Qd6 Bf8 (I calculated 22. ... Ncd3? for a while before finally realizing it just loses after 23.Bxd3 Rad8 24.Qb4! +-) 23.Qf6 Bc8!? declining the repetition; black has exchanged his weakness on d6 for white's valuable h3 pawn, so there is no reason not to continue playing.

We shuffled around for another several moves: 24.Bd4 Bg7 25.Qh4 Ne6 26.Be3 h5 27.Qf2 Qc7 28.Rd2?! (D) Instead 28.a3! would have kept the game balanced.

Black to move

Here is another thematic trick: 28. ... a3! 29.Nxa3 Rxa3 30.bxa3 (I was also ready for 30.Bb6 Qe7 31.bxa3 Nxf3 32.Qxf3? Qh4+ picking up the loose Re1) 30. ... Nxf3 now there are not even any intermezzos because of the mate threat on h2. 31.gxf3 Bxc3 32.Red1 Bxd2 33.Rxd2 Black is clearly better now and I stayed in control, pressing my advantage to a win: 33. ... Qe5 34.Bh3 If white was able to exchange his light squared bishop for my knight he might have counterplay on the dark squares, but I don't allow this. 34. ... Nf4 35.Bxc8 Rxc8 36.Bd4 Qg5 37.Bc3 Ne6 38.Rd1 Rd8 39.Rxd8+ Qxd8 40.Qd2 The endgame is hopeless for white, but keeping the queens on wasn't really an option either since the king on h1 is so exposed. 40. ... Qxd2 41.Bxd2 White's many pawn weaknesses and my passed h-pawn are decisive factors. 41. ... Kf8 42.Kg2 Ke7 43.Be3 Kd6 44.f4 f5 45.exf5 gxf5 46.Kg3 b5 Clearing an avenue for the king 47.cxb5 cxb5 48.Kh4 Kd5 49.Kxh5 Ke4 50.Bb6 Nxf4+ 51.Kg5 Nd5 52.Bg1 f4 53.Kg6 f3 54.Kf7 Ke5 55.Bh2+ Kd4 56.Bg1+ Kc4 57.Ke6 Nc3 58.Kd6 Ne4+ 59.Kc6 f2 60.Bxf2 Nxf2 61.Kb6 Ne4 62.Ka5 Nc3 63.Kb6 Nxa2 64.Kc6 Nc3 65.Kb6 Nb1 66.a4 bxa4 0-1

Heading into the final round, I was leading the field with 5/5 and only Evan Park (2305) had 4.5/5 after having won against Timur Gareyev with black in the previous round. At this point just a draw would secure me clear first.

Paciorkowski, Lev (2443) - Park, Evan (2305); Round 6

Black to move

After declining two draw offers in the opening, we reached this interesting position. Early on I had sent my h-pawn all the way up to h6, but the main question here is whether or not that pawn is a strength or a weakness. I had just castled last move, so there is no longer a rook defending it.

I thought an ambitious way of playing for black would be 16. ... g5!?, when I honestly wasn't entirely sure what to do. The idea is simply ...g4 and ...Bg5 to start rounding up my pawn. During the game I was planning to respond 17.d4 g4 18.Ne5, but I wasn't sure how clear that was since black can still play 18. ... Nxe5 19.fxe5 Bg5. I have to sac a pawn and from afar hadn't seen if I can make strong enough counter threats by doubling on the d-file and putting a rook on d6.

In the game, my opponent did not sense the danger he was facing and played nonchalantly 16. ... Qe7?! 17.Rfd1 Rbc8? (17. ... g5 was essential at this point to get some counterplay) 18.d4 exd4 19.exd4! (D)

Black to move

By far the strongest recapture. I actually think white is already just winning in this position, since black has no way to stop the d4-d5 break, when the center blows open and the king on g8 comes under attack. The Nc6, Bd7 and Qe7 are on perhaps the worst possible squares, as they will only be targets after I put my rooks on e1/d1 and push d5.

The only tactical variation to calculate was 19. ... b5, but it just doesn't work after 20.Bxb5 when I saw 21. ... Nb4? 22.Bxb4 +- and 21. ... Nxd4 22.Nxd4 Bxd4 23.Rxd4 Bxb5 24.Qd2 +- when black's king is fatally weak on the dark squares. Evan had been playing fairly quickly up until this point but started to consume a lot of time as he no doubt started to realize the trouble he was in.

19. ... Kh8 there are hardly better alternatives; 19. ... Na5 20.Bb4 wins the exchange. 20.Qb2 Rcd8 21.Re1 Qd6 22.Rcd1 Ne7 (D)

White to move

With all pistons firing, white is ready to go: 23.d5 exd5 (23. ... Nxd5 24.Bxf6+ Rxf6 25.Qxf6+ Nxf6 26.Rxd6 +-) 24.Bxf6+ Rxf6 (24. ... Qxf6 25.Qxf6+ Rxf6 26.Rxe7 dxc4 27.Rdxd7 +-) 25.Bxd5! From move 23 it had taken me a few minutes to appreciate the strength of this simple recapture, but once you see it, it becomes clear that black is lost. The threat is Be6 or Re6 which cannot be stopped except for 25. ... Nxd5, allowing 26.Rxd5 Qf8 (26. ... Qc6 27.Rxd7) 27.Rxd7! Rxd7 28.Qxf6+! winning. On 25. ... Rf8 I had also seen the cute interference 26.Bf7! +-.

25. ... Bc6 26.Be6 1-0

Monday, August 31, 2020

Simul 2020 Results!

The 2020 CCCR Simul was held on Wednesday, August 26, 2020 at the Rochester Chess Center. In this post I will just briefly summarize the results and comment on some of the games and my playing strategy throughout the event.

Be sure to also check out some photos from the event at our Photo Gallery

Even with the social distancing and safety procedures, we still were able to have 14 players with all spots filled! Although my opponents fought valiantly, in the end I managed to squeeze out 14 full wins after about 2 hours.

Many of the games were quite interesting! To start, let's have a look at what I think was the most instructive one. Coincidentally this was also the game where I felt like I thought the most: 

I played the opening very quickly, but Ryan played well in response, getting a perfectly decent position with black after 15 moves. This may not sound like a big deal but it is an important step to making my life harder in a simul! In many other games I was able to get a superior or outright winning position from the opening and then convert the advantage on autopilot. When I have no advantage though, I need to think a little on how to pose problems for my opponent and induce some mistakes, which may mean taking some risks on my own position. Indeed, had Ryan found 16. ... c4!, I could easily have found myself in trouble.

Perhaps contrary to expectations, in most of these games I never calculated more than 4 or 5 half-moves ahead. The exceptions are notable though; in two of the games I did need to do some moderately deep calculation:


 And the following game as well:

Finally, the last game I'll analyze here contains probably the most amusing moment of the simul: I flat-out missed capturing a free rook!


 Probably for the best, I remained blissfully ignorant of my oversight until after all the games were done.

In what seems to be a new feature, offers some interesting statistics when analyzing games -- to close out I'll share this on the 13 games that we recovered the notation for:

  • Total time: ~ 2 hours
  • Total moves played: 471 (by me only)
  • Average time per move: 15 seconds
  • "Best" move: 254 / 471 (54%)
  • "Excellent" move: 77 / 471 (16%)
  • "Good" move: 53 / 471 (11%)
  • "Book" move: 54 / 471 (11%)
  • "Inaccuracy": 18 / 471 (4%)
  • "Mistake": 12 / 471 (3%)
  • "Blunder": 1 / 471 (<1%)
  • "Missed Win": 2 / 471 (<1%)
  • Average accuracy score: 91%

Thank you very much to all participants and organizers! A lot of planning went into making sure this event would be safe and it was great to see the turnout that we had.

Wednesday, August 19, 2020

Member Games: Adventures in the Queen's Indian

Today we get to look at a highly instructive game played at one of the Saturday tournaments here in Rochester. It is the encounter Beh - Manning, played on 08 August 2020.

The game started off roughly balanced after white's unusual 7.Bg5!? in the Queen's Indian. Later after the imprecise 13.Qc3?! black was able to use the bishops to open the position and get a good game. However, black proceeded to make two serious positional errors -- 19. ... cxd4? and 25. ... Bxe4?, which led his position from being better, to equal, and then to worse. A few moves later, already in a tough spot, 28. ... f5? was the last straw for black's position and white smoothly converted the advantage from there, using a classic "principle of two weaknesses" approach by attacking black's king while tying up his pieces to the advanced passed c-pawn.

Friday, July 31, 2020

How to Calculate (2/2)

Here is the answer to the position from this post on calculation.

I right away got the sense that black's last move ...e6-e5 should give me some chance for a forcing continuation, because the position is opening up and white is a little better coordinated. Also, black is conspicuously lacking a defensive knight on f6 -- instead it is on the terrible b6 square. This means the kingside is weak, and should be my focus.

So, here's what I calculated:
  • After 2.Qh5 Qxd4 3.Ng5 h6, both my Ng5 and Ra1 are hanging. I can save both with 4.Be3 but then at the very least 4. ... Qg4 trades queens and ends my attack. Black is fine there.
  • What about 2.d5!? - after 2. ... cxd5 3.cxd5 black cannot play 3. ... Qxd5? 4.Nf6+! (a tactic) so instead must play 3. ... Nxd5. I can keep going with 4.Ba3 Re8...what do I have in that position? Perhaps 5.Nd6 but then 5. ... Bxd6 6.Bxd6 Qxd6 7.Bxd5 and we have made too many trades, black can at the very least equalize there by returning the pawn with 7. ... Be6 8.Bxb7 Rad8.
  • Going back to the position after 2.d5!? cxd5 3.cxd5 Nxd5 4.Ba3 Re8, how about 5.Nc5!? ... if black moves the Nd5 I take on b7, but maybe the position after 5. ... Be6 6.Nxe6 fxe6 is not too bad...yes, that's a strong knight on d5 now. Although white shouldn't be worse with the bishop pair and black's ugly e-pawns, I want to find something better...
  • How about 2.Ba3 immediately? The rook only has one square: 2. ... Rf8. Hmm, now after 3.Qh5 I am threatening the deadly Ne4-g5, double attacking h7 and f7 ... for example 3. ... Qxd4? 4.Ng5 and black is busted; 4. ... Bf5 5.Qxf7+ and 6.Qxf5, or 4. ... h6 5.Qxf7+ and 6.Qxe8 wins for white
  • So that means after 2.Ba3 Re8 3.Qh5 black must stop Ne4-g5. There are not many ways to do that; 3. ... f6 looks very dubious so probably black must try 3. ... h6 instead.
  • In that case, after 2.Ba3 Re8 3.Qh5 h6 maybe I can try 4.d5 there; I am threatening d5-d6 or simply Rad1 with a crushing position, so black has to try taking: 4. ... cxd5 5.cxd5, but now once again 5. ... Qxd5? 6.Nf6+! wins on the spot, so how about 5. ... Nxd5 instead? In that position, the d-file is open, so I can continue with 6.Rad1, threatening Rxd5 followed by Nf6+, winning. What can black do about that?
  • So, after 2.Ba3 Re8 3.Qh5 h6 4.d5 cxd5 5.cxd5 Nxd5 6.Rad1, black must do something to stop my threat - 6. ... Nf6 is no good because of 7.Rxd8 Nxh5 8.Rxe8+. The queen cannot move though; on any queen move I still have 7.Rxd5. Perhaps 6. ... Kh8, that would stop 7.Rxd5 Qxd5 because 8.Nf6 is no longer check. Instead though, after 6. ... Kh8 I could do something simple like 7.Nc3. The Nd5 is triple attacked and only defended once; if it doesn't move I will simply take it next turn and 7. ... Nf6 is still met by 8.Rxd8 Nxh5 9.Rxe8+, winning
  • OK, so 2.Ba3 Re8 3.Qh5 h6 4.d5 cxd5 5.cxd5 Nxd5 6.Rad1 ... hm ... since ...Kh8 and ...Nf6 don't work, the knight must be defended; only way is 6. ... Be6. What do I have there? Maybe 7.Nc5 again? After 7.Nc5 b6 8.Nxe6 fxe6 once again I've just reinforced that knight on d5; white shouldn't be worse but I want more than that.
  • 2.Ba3 Re8 3.Qh5 h6 4.d5 cxd5 5.cxd5 Nxd5 6.Rad1 Be6 ... maybe 7.Nc3, triple attacking the knight. But there black can get away with 7. ... Nf6 since his rooks are connected: 8.Rxd8 Nxh5 9.Rxe8+ Rxe8 and black is fine.
  • 2.Ba3 Re8 3.Qh5 h6 4.d5 cxd5 5.cxd5 Nxd5 6.Rad1 Be6 ... black's position is quite shaky here ... is it crazy to try 7.Rxd5!? After 7. ... Qxd5 8.Nf6+ wins again, so that means 7. ... Bxd5 is forced. Now I play the other rook 8.Rd1, again threatening Rxd5 and Nf6+. What on earth can black do about that?
  • So my main line right now is 2.Ba3 Re8 3.Qh5 h6 4.d5 cxd5 5.cxd5 Nxd5 6.Rad1 Be6 7.Rxd5 Bxd5 8.Rd1 ... OK, any queen move and I can simply play 9.Rxd5 - for instance 8. ... Qd7 9.Rxd5 Qxd5 10.Nf6+ gxf6 11.Bxd5 and what's material there ... I have queen and bishop for two rooks, and black's king is weak - should be winning for white.
  • After 2.Ba3 Re8 3.Qh5 h6 4.d5 cxd5 5.cxd5 Nxd5 6.Rad1 Be6 7.Rxd5 Bxd5 8.Rd1, what else could black try there... what about 8. ... Kh8 again - a funny move but it stops my main threat, since Nf6 is not check anymore. But there again I could just play 9.Nc3. If you let me take on d5 I have two minors for a rook, should be close to winning position. The only other try is to sac the queen with 9. ... Bxg2 10.Rxd8 Raxd8 11.Kxg2. There again I have queen and minor piece for two rooks; that's winning.
  • So what's left? After 2.Ba3 Re8 3.Qh5 h6 4.d5 cxd5 5.cxd5 Nxd5 6.Rad1 Be6 7.Rxd5 Bxd5 8.Rd1, ...Kh8 is no good, queen moves are no good, maybe 8. ... Bc6 but then still 9.Rxd8 Raxd8 with Q+N for two rooks; that's decisive. If 8. ... g6 then just 9.Qxh6, that doesn't help black at all. OK, this line is good for me, so black must find something else earlier.
  • After 2.Ba3 Re8 3.Qh5 h6 4.d5 cxd5 5.cxd5 Nxd5 6.Rad1 Be6 7.Rxd5 the only move other than 7. ... Bxd5 is 7. ... Qxd5 and sac the queen: 8.Nf6+ gxf6 9.Bxd5 Bxd5; there black has rook and bishop for the queen, but wait, the line continues: I have 10.Qg4+ Kh7 and 11.Qd7, picking up a bishop, so white should be easily winning there.
  • So I suppose then after 2.Ba3 Re8 3.Qh5 h6 4.d5 cxd5 5.cxd5, black cannot play 5. ... Nxd5 because 6.Rad1 is just too strong. 6. ... Be6 7.Rxd5 is winning for white, but there is nothing else there for black to meet both Rxd5-Nf6 and the simple Nc3.
  • In that case, my main line is 2.Ba3 Re8 ... that's forced ... 3.Qh5 h6 ... that's also forced, to stop Ng5 ... 4.d5 cxd5 5.cxd5. If black cannot play 5. ... Nxd5 then my next moves are either d5-d6 or Rad1, which looks like a nearly winning position for white.
This whole process took me about 15 minutes of completely focused thought, and the game continued 2.Ba3 Re8 3.Qh5 h6 4.d5! cxd5 5.cxd5 After some thought black could find nothing better than 5. ... f5?! - this wasn't a move I calculated, but there was no need to: at the very least I can always retreat with 6.Nc3 and retain the strong pawn on d5 or 6.Nc5 planning to meet 6. ... Nxd5 with 7.Rad1. After thinking I found the stronger 6.d6! Bb8 7.Nc5 and won quickly.

Now, if you also sat down and calculated this position for a good length of time, we can analyze your thinking process. It doesn't matter if you didn't see everything or if you made mistakes - we can identify those things as places to improve. In general, I find that people make three main kinds of mistakes when calculating (all of these can be reduced with specific types of exercises):
  1. Technical Errors - for example the "ghost piece": after Bc1-a3 you try to move the bishop again from c1 to g5 later in a variation; or after a piece gets captured you still try to make moves with it on the board. This is very common, and I've even seen GMs do this on occasion!
  2. Tactical Errors - overlooking a tactical shot in a variation in your head. Everybody is vulnerable to this, even masters and grandmasters.
  3. "Blind spots" - This can vary from person to person. For instance, do you often miss sideways queen moves or backwards moves (many people struggle with those). Or maybe you frequently overlook simpler "quiet" moves. Regularly missing defensive resources or your opponent's counterplay could also be a blind spot.
To wrap up, how can we improve?
Technical Errors:
These mistakes we make because beyond a certain depth the position starts to get "fuzzy" and we no longer have a clear grasp on where the pieces are. The critical depth this happens at can vary a lot from person to person, but it can also depend on other things like your level of focus and if you're hungry or tired etc.

If you did the exercise, you can roughly estimate your maximum depth - go back and find the longest variation that you calculated. Even if the variation isn't relevant to the solution, as long as all the moves are legal, record its depth as the total number of half-moves made for each side. For example, my maximum depth was 19 in the variation 2.Ba3 Re8 3.Qh5 h6 4.d5 cxd5 5.cxd5 Nxd5 6.Rad1 Be6 7.Rxd5 Qxd5 8.Nf6+ gxf6 9.Bxd5 Bxd5 10.Qg4+ Kh7 11.Qd7. From what I've heard anecdotally, a typical GM can do around depth 25 comfortably! Most positions do not require that level of depth to find the right solution though. Consistently being able to visualize at depth 10 (five moves ahead for both sides) is plenty good enough for most situations.

You can improve your depth with visualization exercises:
  • At the basic level, just start with having a friend tell you the name of a square on the chessboard. Without looking, say what color that square is (e.g. "c4: white").
  • Find a friend and an empty chess board. Have your friend put any two pieces on the empty board on any two squares (color doesn't matter). Without looking, say if any of the pieces attacks the other. Then have your friend make a move with one of the pieces, telling it to you out loud. Repeat, saying if any of the pieces attacks the other, but without looking. This can be scaled up with more pieces for greater difficulty.
  • Try to win a simple position (e.g. mate with king and queen vs. king) blindfolded against a friend, only saying the moves.
  • Find any game and read through the first 5-10 moves. Then, go to a chess board and set up how you see the position resulting from those 5-10 moves, comparing it to how the position actually is.
Some people find these exercises easier or harder than others, and your visualization ability is not necessary correlated to rating. Doing calculation exercises like the position we did in this post will also naturally stretch your depth, as will solving puzzles without moving the pieces.

Tactical Errors:
Even if we can perfectly visualize a position at depth 10, sometimes we still overlook a one or two-move tactical shot. For example, if you analyzed 2.Ba3 Re8 3.Qh5 h6 4.d5 cxd5 5.cxd5 Nxd5 6.Rad1 and clearly visualized that position but didn't notice that you were threatening Rxd5 followed by Nf6+, you would have made a tactical, not technical error.

Most of the time, I find that tactical and technical errors actually tend to go together, and the logic is straightforward: if the position is getting fuzzy, you're less likely to notice a key tactical idea. For this reason, training your depth will also tend to improve your ability to see tactics in any variations you analyze.

However, another solution is to simply practice solving basic tactical puzzles. All of these tactics are really just patterns, and pattern-recognition is something our brains are naturally good at. Those forks, pins, skewers, discovered attacks and basic checkmating patterns frequently repeat themselves throughout chess games, and simply taking the time to regularly solve puzzles - even just 15 minutes a day - will put you on the road to mastering them. Of the three kinds of errors here, tactical errors are the easiest to train. This is why one of the very first things I teach my students is how to solve tactics so they are able to find those simple one-move shots in a position.

Blind Spots:
Last but not least, we have the tricky ones, where for some reason, you frequently overlook certain types of moves. Rest assured it is not just you -- the following are generally tricky for everybody:
  • Backwards moves
  • Long sideways queen/rook moves
  • "Co-linear" moves (you move towards an opponent's piece but stop just short of capturing it)
  • Quiet moves, particularly in non-quiet positions
  • Forgetting about/overlooking opponent's counterplay
I personally chalk these up to pattern recognition, because usually we have blind spots for unusual or unexpected moves that break patterns. However, with more experience calculating I've noticed these gradually fade away from my own thought process. A big part of overcoming blind spots is knowing that they exist and to specifically make yourself look for them while you're thinking. For example, if I'm stuck on a position I might literally ask myself, "do I have any quiet moves here?" to force myself to look for them.