Personal test position: Can you see the follow-up?

[Albert Silver]

Here is a combination I played in the state championship here:

[D]r2q1r2/1p1nnp1k/p6p/3pPN2/1P3P2/P4Q2/2P3PP/4RR1K w - -

I had just sacced a knight one move earlier. The first move is easy enough to see, but can you see the follow-up? It is what makes it special IMHO.

1.Nxh6! that's the easy part. 1...Kxh6

[D]r2q1r2/1p1nnp2/p6k/3pP3/1P3P2/P4Q2/2P3PP/4RR1K w - -

2.f5!! No capture, and no check! 2...Ng6 3.f6!! Again no capture and no check despite two pieces down.

To be honest, though this was the mainline I had analyzed, along with 2...Rh8 (also answered by 3.f6!!), my opponent played 2...f6 and resigned after 3.Qh3+ Kg7 4.Qg4+ Kf7 (we were both in extreme time trouble at this point) 5.e6+ 1-0

[Dann Corbit]

Can we see the complete game score?

[rightrook]

Great playing...

.it looks like about a mate in 18 when I enter the same moves you made....

Nxh6.........should be a good test move for engines to find.

regards

Robert

[Terry McCracken]

Here is a combination I played in the state championship here:

[D]r2q1r2/1p1nnp1k/p6p/3pPN2/1P3P2/P4Q2/2P3PP/4RR1K w - -

I had just sacced a knight one move earlier. The first move is easy enough to see, but can you see the follow-up? It is what makes it special IMHO.

1.Nxh6! that's the easy part. 1...Kxh6

[D]r2q1r2/1p1nnp2/p6k/3pP3/1P3P2/P4Q2/2P3PP/4RR1K w - -

2.f5!! No capture, and no check! 2...Ng6 3.f6!! Again no capture and no check despite two pieces down.

To be honest, though this was the mainline I had analyzed, along with 2...Rh8 (also answered by 3.f6!!), my opponent played 2...f6 and resigned after 3.Qh3+ Kg7 4.Qg4+ Kf7 (we were both in extreme time trouble at this point) 5.e6+ 1-0

Nicely Played!

If you don't mind...Could you provide the PGN Players and Event?

Thanks!

Terry

[kgburcham]

[D] r2q1r2/1p1nnp1k/p6p/3pPN2/1P3P2/P4Q2/2P3PP/4RR1K w - - 0 1


1.Nxh6
+/- (1.20) :46
1.Nxh6
+- (1.65) :53
1.Nxh6 Kxh6 2.Qh3+ Kg7 3.f5 Rh8 4.f6+ Kg8 5.fxe7 Qxe7 6.Qg4+ Kf8 7.e6 Nf6 8.Qf4 Ne4 9.c4 Rh4 10.Qxf7+ Qxf7 11.Rxf7+ Ke8 12.cxd5 Rd8 13.Rd1 Nc3 14.Rc1 Nxd5
+- (1.77) :59
1.Nxh6
+- (2.02) 1:38
1.Nxh6 Qb6 2.Ng4 Qg6 3.Qh3+ Kg7 4.f5 Nxf5 5.Ne3 Nxe3 6.Rxe3 Nxe5 7.Rg3 Rae8 8.Qh4 b5 9.Rxg6+
+- (3.21) 5:34

[Anil]

Nice game. Congrats on the victory.

I think, ProDeo 1.6 is one of the fastest chess engines in this position, getting the knight sacrifice in a fraction of a second.

FEN: r2q1r2/1p1nnp1k/p6p/3pPN2/1P3P2/P4Q2/2P3PP/4RR1K w - - 0 1

Rebeluci:
1 00:00 10 10.000 -0.21 Nf5xe7 Qd8xe7 Qf3xd5
1 00:00 35 35.000 +0.54 Qf3h5
1 00:00 65 65.000 +0.90 Qf3g4
2 00:00 203 203.000 -0.53 Qf3g4 Ne7xf5 Qg4xf5+ Kh7h8
2 00:00 442 442.000 -0.19 Nf5xe7 Qd8xe7 Qf3d3+ Kh7h8 Qd3xd5
3 00:00 997 997.000 -0.07 Nf5xe7 Qd8xe7 Qf3xd5 Nd7b6 Qd5d3+ Kh7g8
3 00:00 1.497 1.497.000 -0.03 Nf5d6 b7b5 Qf3g4
4 00:00 5.038 5.038.000 -0.20 Nf5d6 b7b5 Qf3d3+ Kh7h8
4 00:00 7.390 7.390.000 -0.07 Nf5xe7 Qd8xe7 Qf3xd5 Nd7b6 Qd5d3+ Kh7g8
5 00:00 15.536 15.536.000 +0.01 Nf5xe7 Qd8xe7 Qf3xd5 Nd7b6 Qd5d3+ Kh7h8
6 00:00 41.307 41.307.000 +0.10 Nf5xe7 Qd8xe7 Qf3xd5 Nd7b6 Qd5d3+ Kh7g8 c2c4
7 00:00 83.756 83.756.000 +0.03 Nf5xe7 Qd8xe7 Qf3xd5 Nd7b6 Qd5d3+ Kh7h8 c2c4 Rf8g8
8 00:00 193.694 193.694.000 +0.13 Nf5xe7 Qd8xe7 Qf3xd5 Nd7b6 Qd5d4 Nb6a4 Qd4d3+ Kh7g8 c2c4
9 00:00 447.969 447.969.000 +0.23 Nf5xe7 Qd8xe7 Qf3xd5 Nd7b6 Qd5e4+ f7f5 e5xf6/ep+ Qe7xe4 Re1xe4 Rf8xf6 Re4e7+ Kh7g6 Re7xb7 Ra8e8 f4f5+ Kg6g5
9 00:00 841.521 841.521.000 +0.33 Nf5xh6 Kh7xh6 Qf3h3+ Kh6g7 f4f5 Rf8h8 f5f6+ Kg7g8 f6xe7 Qd8xe7 Qh3g3+ Kg8f8 e5e6 Nd7f6 e6xf7 Qe7xf7 h2h3
10 00:01 1.943.829 1.943.829 +0.58 Nf5xh6 Kh7xh6 Qf3h3+ Kh6g7 f4f5 f7f6 Re1e3 Rf8g8 e5e6 Nd7e5 Qh3h4
11 00:06 9.657.104 1.609.517 +1.01 Nf5xh6 Kh7xh6 f4f5 Ne7g6 f5f6 Nd7xf6 Qf3e3+ Kh6h7 Qe3h3+ Kh7g8 e5xf6 Rf8e8 Qh3h6
12 00:44 69.180.937 1.572.294 +2.00 Nf5xh6 Qd8b6 e5e6 Kh7xh6 e6xd7 Qb6f6 Re1e5 Kh6g7 Qf3g4+ Ne7g6 Re5xd5 Kg7h8
13 00:54 83.320.452 1.542.971 +1.81 Nf5xh6 Qd8b6 e5e6 Kh7xh6 e6xd7 Qb6f6 Re1e5 Kh6g7 Qf3g4+ Ne7g6 Re5xd5 Kg7h8 c2c4 Ra8d8

[Albert Silver]

Can we see the complete game score?

Unfortunately, I don't have the complete score. The game was played a few years back, and I had it saved in a file just called "Personal Tactics". I have plenty of others, though this is the only one the engines (most) still take time on. I'll share a few.

My opponent was rated around 2100 FIDE at the time, so I had a rating edge, and I recall having some 20 minutes left on the clock left to finish the game, and spending at least 12 of my last 14 minutes to make the second knight sac. No check and no capture look great on paper, but I wasn't keen on looking like a complete idiot to my colleagues if I lost....

That said, it starts just before the first knight sac, so here goes:

[D]r2q1r2/1p1n1p1k/p3p1np/3pPp2/1P1N1P2/P4QN1/2P3PP/4RR1K w - - 0 1

[Event "Rio de Janeiro State Championship"]
[Site ""]
[Date "2000"]
[Round ""]
[White "Silver, Albert "]
[Black "Moraes Da Silva, Paolo"]
[Result "1-0"]
[Eco ""]
[Annotator "Albert Silver"]
[Source ""]
[SetUp "1"]
[FEN "r2q1r2/1p1n1p1k/p3p1np/3pPp2/1P1N1P2/P4QN1/2P3PP/4RR1K w - - 0 1"]

1. Ndxf5 exf5 2. Nxf5 Ne7 3. Nxh6 Kxh6 4. f5 f6 (4... Rh8 5. f6) (4... Ng6 5. f6) 5. Qh3+ Kg7 6. Qg4+ Kf7 7. e6+ 1-0

[Terry McCracken]

Thanks Albert!

That is a very slick and Classic Destruction of the Kingside, I enjoyed it. And I saved it!

Terry

[Eelco de Groot]

There is some bug lurking in the Ancalagon evaluation routine of passed pawns so that now even in this position, without any passed pawns, it cripples the search. I have not found the bug yet, probably many lines that are now wrong, but as an emergency measure I can switch off giving a score to them and that certainly helps finding the solution. I let the search run quite long but because passed pawns are either evaluated false or not at all, this means the variations have to be taken with a pinch of salt.

Passed Pawns =100 but totally buggy passed pawn eval:

[D]r2q1r2/1p1nnp1k/p6p/3pPN2/1P3P2/P4Q2/2P3PP/4RR1K w - -

Engine: Ancalagon 1.1 Beta 1 Build 27 (Athlon 2009 MHz, 256 MB)
by Tord Romstad, Eelco de Groot

9.00 0:00 +2.07 3.Nh4 Rg8 4.e6 fxe6 5.Rxe6 Nf8
6.Qd3+ Neg6 7.Nxg6 Rxg6 8.Re5 (216.089) 276

10.01 0:02 +2.21 3.Nh4 Rc8 4.Qd3+ Kh8 5.Rc1 Ng6
6.Nxg6+ fxg6 7.Qxg6 Qe7 8.Qxh6+ Kg8
9.e6 Qh4 (864.289) 354

11.01 0:03 +1.64 3.Nh4 Rc8 4.Qd3+ Kh8 5.Rc1 Ng6
6.Nxg6+ fxg6 7.e6 Nb6 8.Qxg6 Rf6
9.Qg4 Qe7 (1.348.991) 367

11.04 0:05 +2.31 3.Nxe7 Qxe7 4.Qxd5 Rad8 5.Qxb7 Qe6
6.Rd1 Rg8 7.Rd6 Qf5 8.Qxa6 Qh5 (2.145.879) 389

11.07 0:06 +2.39 3.Nd6 Ng6 4.Qh3 Ne7 5.e6 fxe6 6.Qxe6 Nc6
7.Nf5 Rxf5 8.Qxf5+ Kg7 9.Qxd5 (2.526.145) 390

12.01 0:10 +2.45 3.Nd6 f5 4.Qh5 Qb6 5.Nf7 Qg6 6.Qxg6+ Kxg6
7.e6 Nf6 8.Rf3 Kg7 9.Nd6 Ne4 (4.210.234) 391

13.01 0:25 +3.25 3.Nd6 Rc8 4.Qd3+ Ng6 5.Nxc8 Qxc8
6.e6 fxe6 7.Rxe6 Rf6 8.f5 Kg8 9.Rxf6 Nxf6
10.fxg6 Qe6 11.Qg3 Qg4 (10.063.915) 392

14.01 0:32 +3.25 3.Nd6 Rc8 4.Qd3+ Ng6 5.Nxc8 Qxc8
6.e6 fxe6 7.Rxe6 Rf6 8.f5 Kg8 9.Rxf6 Nxf6
10.fxg6 Qe6 11.Qg3 Qg4 (13.012.170) 396

15.01 1:12 +3.11 3.Nd6 Rc8 4.Qd3+ Ng6 5.Nxc8 Qxc8
6.e6 fxe6 7.Rxe6 Rf6 8.f5 Nge5
9.Re7+ Kh8 10.Qxd5 Qf8 11.Rxd7 Nxd7
12.Qxd7 Kg8 (28.765.242) 397

16.01 2:55 +3.17 3.Nd6 Rc8 4.Qd3+ Ng6 5.e6 fxe6
6.Nxc8 Qxc8 7.Rxe6 Rf6 8.f5 Nge5
9.Re7+ Kh8 10.Qxd5 Qf8 11.Rxd7 Nxd7
12.Qxd7 Qg7 13.Qe8+ Kh7 (69.657.712) 397

17.01 12:01 +3.64 3.Nd6 Rc8 4.Qd3+ Ng6 5.e6 fxe6
6.Nxc8 Rf6 7.Nd6 b5 8.f5 Nge5 9.Qe2 Qe7
10.fxe6 Qxe6 11.Rxf6 Qxf6 12.Ne8 Kg8 (282.707.788) 391

18.01 21:05 +3.58 3.Nd6 Rc8 4.Qd3+ Ng6 5.e6 fxe6
6.Nxc8 Rf6 7.Nd6 Qb8 8.Nc4 b5 9.f5 bxc4
10.fxg6+ Kh8 11.Qc3 Qf8 12.Rxe6 Kg8
13.Rfxf6 Nxf6 (496.800.591) 392

19.01 68:10 +3.74 3.Nd6 Ng6 4.Qh3 Nf6 5.Nxb7 Qb6
6.exf6 Qxf6 7.Nc5 Rfd8 8.Qd3 Ra7
9.Qg3 Qf5 10.Re2 Qf6 11.Qd3 Kg7
12.f5 (1.615.273.781) 394

19.03 112:19 +5.90 3.Nxh6 Kxh6 4.f5 Ng8 5.Qh3+ Kg7
6.Qg4+ Kh7 7.f6 Ngxf6 8.exf6 Nxf6
9.Qh4+ Kg6 10.Re5 Nh7 11.Qh5+ Kg7
12.Rxd5 Kh8 13.Rxd8 Raxd8 14.Qe5+ f6
15.Qe4 b6 16.c4 (2.590.603.886) 384

20.01 199:16 +7.00 3.Nxh6 Ng6 4.Nf5 Rh8 5.Qxd5 Qe8 6.e6 Nf6
7.Qxb7 Rb8 8.Qxf7+ Qxf7 9.exf7 Rhf8
10.Nd6 Kg7 11.Re6 Rxf7 12.c4 Kg8
13.c5 Nf8 14.Nxf7 Nxe6 15.Ne5 (4.457.263.509) 372

21.01 409:22 +7.66 3.Nxh6 Qb6 4.e6 fxe6 5.Qh3 Ng6
6.Rxe6 Qxe6 7.Qxe6 Nde5 8.Nf5 Rae8
9.Qxd5 Rxf5 10.Qxb7+ Kg8 11.Qxa6 Nxf4
12.a4 Rff8 13.a5 Rc8 14.c4 Rxc4
15.b5 (8.984.493.697) 365

best move: Nf5xh6 time: 417:52.734 min n/s: 366.258 nodes: 9.183.090.000

Passed Pawns = 0 so no passed pawn eval, same build of the engine:

r2q1r2/1p1nnp1k/p6p/3pPN2/1P3P2/P4Q2/2P3PP/4RR1K w - -

Engine: Ancalagon 1.1 Beta 1 passedpawns 0 (256 MB)
by Tord Romstad, Eelco de Groot

9.00 0:00 +2.25 3.Qd3 Nxf5 4.Qxf5+ Kh8 5.Rf3 Rg8
6.Rh3 Qb6 7.e6 Rg6 8.exd7 Rf8 (134.281) 245

10.00 0:00 +2.01 3.Qd3 Nxf5 4.Qxf5+ Kh8 5.Rf3 Rg8
6.Rh3 Rg6 7.Qxf7 Qe8 8.Qxd5 Qe6
9.Qxb7 (225.918) 294

11.01 0:01 +2.01 3.Qd3 Nxf5 4.Qxf5+ Kh8 5.Rf3 Rg8
6.Rh3 Rg6 7.Qxf7 Qe8 8.Qxd5 Qe6
9.Qxb7 (488.296) 351

11.02 0:01 +2.29 3.Qh5 Nxf5 4.Qxf5+ Kh8 5.Rf3 Qe7
6.Qh5 f5 7.Rh3 Qg7 8.Rg3 Rf7 (538.375) 355

12.01 0:02 +1.74 3.Qh5 Nxf5 4.Qxf5+ Kh8 5.Rf3 Rg8
6.Rh3 Rg6 7.Qxf7 Qe8 8.Qxd5 Qe6
9.Qxe6 Rxe6 10.Kg1 (1.138.845) 383

12.02 0:03 +2.01 3.Qd3 Nxf5 4.Qxf5+ Kh8 5.Rf3 Rg8
6.Rh3 Rg6 7.Qxf7 Qe8 8.Qxd5 Qe6
9.Qxb7 (1.263.842) 388

13.01 0:07 +1.74 3.Qd3 Nxf5 4.Qxf5+ Kh8 5.Rf3 Rg8
6.Rh3 Rg6 7.Qxf7 Qe8 8.Qxd5 Qe6
9.Qxe6 Rxe6 10.Kg1 (2.942.687) 399

13.03 0:19 +2.94 3.Nxh6 Kxh6 4.f5 f6 5.Qh3+ Kg7
6.Qg4+ Kh8 7.Rf3 Rf7 8.Rh3+ Rh7
9.Rxh7+ Kxh7 10.Re3 Qf8 11.Rh3+ Qh6
12.Rxh6+ Kxh6 13.Qh4+ Kg7 14.exf6+ Nxf6
15.Qg5+ Kf7 16.a4 (7.233.075) 372

14.01 0:27 +2.94 3.Nxh6 Kxh6 4.f5 f6 5.Qh3+ Kg7
6.Qg4+ Kh8 7.Rf3 Rf7 8.Rh3+ Rh7
9.Rxh7+ Kxh7 10.Re3 Qf8 11.Rh3+ Qh6
12.Rxh6+ Kxh6 13.Qh4+ Kg7 14.exf6+ Nxf6
15.Qg5+ Kf7 16.a4 (10.182.058) 374

15.01 2:08 +4.90 3.Nxh6 Kxh6 4.f5 Rh8 5.f6 Kh7 6.e6 Ng6
7.Qh5+ Kg8 8.exf7+ Kxf7 9.Re7+ Qxe7
10.fxe7+ Kg7 11.e8N+ Raxe8 12.Qf5 Rhf8
13.Qxd7+ Kh6 14.Kg1 Rxf1+ 15.Kxf1 (46.513.949) 361

16.01 4:24 +4.37 3.Nxh6 Qb6 4.e6 Kxh6 5.exd7 Qf6
6.Re5 Rg8 7.g3 Rad8 8.Rfe1 Nf5
9.Qxd5 Qc6 10.Qxc6+ bxc6 11.Rxf5 Rxd7
12.Kg1 Rd2 (95.365.200) 360

17.01 9:03 +4.19 3.Nxh6 Qb6 4.e6 Kxh6 5.exd7 Qf6 6.f5 Rfd8
7.Qg4 Rg8 8.Qf4+ Qg5 9.Qxg5+ Rxg5
10.Rxe7 f6 11.Kg1 Rh8 12.Rf3 Rgg8
13.Kf2 Kg5 (198.043.811) 364

18.01 18:18 +4.15 3.Nxh6 Qb6 4.e6 Kxh6 5.exd7 Qf6 6.f5 Rfd8
7.Qg4 Rg8 8.Qf4+ Kh7 9.Qe3 Raf8
10.Qh3+ Qh6 11.Qxh6+ Kxh6 12.Rxe7 b6
13.Re3 Kg5 14.Kg1 Kh5 (394.438.842) 359

19.01 45:21 +4.05 3.Nxh6 Qb6 4.e6 Kxh6 5.exd7 Qf6 6.f5 Rg8
7.Qf4+ Kh7 8.Qe3 Kg7 9.Qxe7 Qxe7
10.Rxe7 Kf6 11.d8B Rgxd8 12.Rxb7 Rdb8
13.Rd7 Rd8 14.Rxd8 Rxd8 15.Kg1 (986.521.302) 362

20.01 131:58 +3.86 3.Nxh6 Qb6 4.e6 Kxh6 5.exd7 Qf6
6.Qe3 Nf5 7.Qd3 Nh4 8.Qxd5 Qg7 9.Re3 Qxg2+
10.Qxg2 Nxg2 11.Kxg2 Rg8+ 12.Kf3 Rad8
13.Rd1 b5 14.Ke4 Rg6 15.Rh3+ Kg7
16.Rd5 (2.879.096.677) 363

best move: Nf5xh6 time: 153:26.172 min n/s: 366.065 nodes: 3.370.050.000

Eelco