## WAC.002 by evaluation?

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### WAC.002 by evaluation?

A common chess endgame rule says "two connected passers on the sixth beat a rook". Is there any program that happens to solve WAC.002 by eval?

[D]8/7p/5k2/5p2/p1p2P2/Pr1pPK2/1P1R3P/8 b - -

[D]8/7p/5k2/5p2/p1p2P2/Pr1pPK2/1P1R3P/8 b - -

### Re: WAC.002 by evaluation?

[D] 8/7p/5k2/5p2/p1p2P2/Pr1pPK2/1P1R3P/8 b - -

Stockfish 1.7

22.00 0:01 -5.01 1...Rxb2 2.Rxb2 c3 3.Rb6+ Kg7 4.Rb7+ Kh6 5.Rb6+ Kh5 6.Rf6 c2 7.Rxf5+ Kh6 8.Rf6+ Kg7 9.Rd6 c1Q 10.Rd7+ Kf6 11.Rd6+ Kf7 12.Rxd3 Ke6 13.Ke2 Qb2+ 14.Kf3 Qxh2 (17.259.716) 11063

23.01 0:04 -7.55 1...Rxb2 2.Rxb2 c3 3.Rb6+ Ke7 4.Rb7+ Kd6 5.Rb6+ Kc5 6.Rb8 c2 7.Rc8+ Kd6 8.Rd8+ Ke6 9.e4 c1Q 10.exf5+ Kxf5 11.Rd5+ Ke6 12.Rxd3 Qf1+ 13.Ke4 Qh1+ 14.Rf3 Qxh2 (54.881.696) 12258

24.01 0:05 -7.87 1...Rxb2 2.Rxb2 c3 3.Rb6+ Ke7 4.Rb7+ Kd6 5.Rb6+ Kc5 6.Rb8 c2 7.Rc8+ Kd6 8.Rd8+ Ke6 9.e4 c1Q 10.exf5+ Kxf5 11.Rd5+ Ke6 12.Rxd3 Qf1+ 13.Ke4 Qh1+ 14.Rf3 Qxh2 (71.470.176) 12587

25.01 0:06 -8.16 1...Rxb2 2.Rxb2 c3 3.Rb6+ Ke7 4.Rb7+ Kd6 5.Rb6+ Kc5 6.Rb8 c2 7.Rc8+ Kd6 8.Rd8+ Ke6 9.e4 c1Q 10.exf5+ Kxf5 11.Rd5+ Ke6 12.Rxd3 Qf1+ 13.Ke4 Qh1+ 14.Rf3 Qxh2 (88.514.722) 12867

26.01 0:09 -8.60++ 1...Rxb2 2.Rd1 d2 3.Ke2 c3 4.Rg1 d1N+ 5.Kxd1 Rb1+ 6.Kc2 Rxg1 7.h3 Re1 8.Kxc3 Rxe3+ 9.Kb4 Ke6 10.Kxa4 Rxh3 (127.390.465) 13409

26.01 0:10 -8.60 1...Rxb2 2.Rxb2 c3 3.Rb6+ Ke7 4.Rb7+ Kd6 5.Rb6+ Kc5 6.Rb8 c2 7.Rc8+ Kd6 8.Rd8+ Ke6 9.e4 c1Q 10.exf5+ Kxf5 11.Rd5+ Ke6 12.Rxd3 Qf1+ 13.Ke4 Qh1+ 14.Rf3 Qxh2 (136.748.054) 13423

27.01 0:13 -9.21++ 1...Rxb2 2.Rd1 d2 3.Ke2 c3 4.Rg1 d1N+ 5.Kxd1 Rb1+ 6.Kc2 Rxg1 7.h3 Re1 8.Kxc3 Rxe3+ 9.Kb4 Ke6 10.Kxa4 Rxh3 (179.988.825) 13719

27.01 0:14 -9.21 1...Rxb2 2.Rxb2 c3 3.Rb6+ Ke7 4.Rb7+ Kd6 5.Rb6+ Kc5 6.Rb8 c2 7.Rc8+ Kd6 8.Rd8+ Ke6 9.e4 c1Q 10.exf5+ Kxf5 11.Rd5+ Ke6 12.Rxd3 Qf1+ 13.Ke4 Qh1+ 14.Rf3 Qxh2 (194.228.484) 13757

28.01 0:20 -10.06++ 1...Rxb2 2.Rd1 d2 3.Ke2 c3 4.Rg1 d1N+ 5.Kxd1 Rb1+ 6.Kc2 Rxg1 7.h3 Re1 8.Kxc3 Rxe3+ 9.Kb4 Ke6 10.Kc4 Rxa3 (282.963.010) 14115

28.01 0:26 -10.46 1...Rxb2 2.Rxb2 c3 3.Rb6+ Ke7 4.Rb7+ Kd6 5.Rb6+ Kc5 6.Rb8 c2 7.Rc8+ Kd6 8.Rd8+ Ke6 9.Rxd3 c1Q 10.Ke2 Qb2+ 11.Kf3 Qxh2 12.Rc3 Qh3+ 13.Kf2 Qh4+ 14.Ke2 Qh1 (387.250.910) 14365

29.01 0:41 -12.04++ 1...Rxb2 2.Rd1 d2 3.Ke2 c3 4.Rg1 d1N+ 5.Ke1 Nxe3 6.Rg8 Ng2+ 7.Kd1 Nxf4 8.Rf8+ Ke6 9.Rd8 Ke7 10.Rc8 Rd2+ 11.Kc1 Nd3+ 12.Kb1 Rb2+ 13.Ka1 c2 (605.375.512) 14528

29.01 0:53 -12.40 1...Rxb2 2.Rxb2 c3 3.Rb6+ Ke7 4.Rb7+ Kd6 5.Rb6+ Kc5 6.Rb8 c2 7.Rc8+ Kd6 8.Kf2 d2 9.Rxc2 d1Q 10.Rc8 Qb3 11.Rd8+ Ke7 12.Ra8 Qxa3 13.Ra7+ Ke6 14.Rxh7 Qb2+ (788.246.198) 14633

30.01 1:04 -13.33 1...Rxb2 2.Rxb2 c3 3.Rb6+ Ke7 4.Rb7+ Kd6 5.Rb6+ Kc5 6.Rb8 c2 7.Rc8+ Kd6 8.Kf2 d2 9.Rxc2 d1Q 10.Rc8 Qb3 11.Rd8+ Ke7 12.Ra8 Qxa3 13.Ra7+ Ke6 14.Ke2 Qa2+ (949.161.964) 14710

31.01 1:29 -13.61 1...Rxb2 2.Rxb2 c3 3.Rb6+ Ke7 4.Rb7+ Kd6 5.Rb6+ Kc5 6.Rb8 c2 7.Rc8+ Kd6 8.Rd8+ Ke6 9.Rxd3 c1Q 10.Ke2 Qb2+ 11.Kf3 Qxh2 12.Rc3 Qh1+ 13.Kf2 Qa1 14.Rd3 Qa2+ (1.326.025.290) 14850

32.01 1:44 -14.38++ 1...Rxb2 2.Rd1 d2 3.Ke2 c3 4.Rg1 d1N+ 5.Ke1 Nxe3 6.Rg8 Ng2+ 7.Kd1 Nxf4 8.Rf8+ Ke6 9.Rd8 Ke7 10.Rc8 Rd2+ 11.Kc1 Nd3+ 12.Kb1 Rb2+ 13.Ka1 c2 (1.550.681.044) 14811

32.01 2:03 -15.15++ 1...Rxb2 2.Rd1 d2 3.Ke2 c3 4.Rg1 d1N+ 5.Kxd1 Rb1+ 6.Kc2 Rxg1 7.h3 Re1 8.Kd3 c2 9.Kxc2 Rxe3 10.Kd2 Rxa3 11.h4 h5 12.Ke2 Ke6 13.Kd2 Rb3 14.Kc2 Rf3 (1.838.208.520) 14825

32.01 2:05 -15.15 1...Rxb2 2.Rxb2 c3 3.Rb6+ Ke7 4.Rb7+ Kd6 5.Rb6+ Kc5 6.Rb8 c2 7.Rc8+ Kd6 8.Rd8+ Ke6 9.Rc8 d2 10.Rc6+ Kf7 11.Rxc2 d1Q+ 12.Re2 Ke6 13.h4 Qf1+ 14.Rf2 Qd3 (1.858.181.273) 14809

33.01 2:14 -13.45-- 1...Rxb2 2.Rxb2 c3 3.Rb6+ Ke7 4.Rb7+ Kd6 5.Rb6+ Kc5 6.Rb8 c2 7.Rc8+ Kd6 8.Rd8+ Ke6 9.e4 fxe4+ 10.Kxe4 c1Q 11.f5+ Kf6 12.Rd6+ Kg5 13.Rxd3 Qf4+ 14.Kd5 (2.003.172.061) 14855

33.01 2:43 -16.84++ 1...Rxb2 2.Rxb2 c3 3.Rb6+ Ke7 4.Rb7+ Kd6 5.Rb6+ Kc5 6.Rb8 c2 7.Rc8+ Kd6 8.Rd8+ Ke6 9.e4 fxe4+ 10.Kxe4 c1Q 11.f5+ Kf6 12.Rd6+ Kg5 13.Rxd3 Qf4+ 14.Kd5 Qxh2 (2.416.769.062) 14778

33.01 3:53 -17.65 1...Rxb2 2.Rxb2 c3 3.Rb6+ Ke7 4.Rb7+ Kd6 5.Rb6+ Kc5 6.Rb8 c2 7.Rc8+ Kd6 8.Rd8+ Ke6 9.Rxd3 c1Q 10.Ke2 Qb2+ 11.Kd1 Qxh2 12.Rd2 Qh1+ 13.Ke2 Qa1 14.Rd3 Qb2+ (3.430.147.205) 14709

34.01 6:35 -20.92++ 1...Rxb2 2.Rd1 d2 3.Ke2 c3 4.Rf1 d1Q+ 5.Kxd1 Rb1+ 6.Kc2 Rxf1 7.Kxc3 Rh1 8.h4 Rxh4 9.Kb4 h5 10.Kxa4 Rh1 11.Kb3 h4 12.a4 h3 13.Kb2 Rh2+ 14.Ka3 Re2 (5.723.776.338) 14463

Stockfish 1.7

22.00 0:01 -5.01 1...Rxb2 2.Rxb2 c3 3.Rb6+ Kg7 4.Rb7+ Kh6 5.Rb6+ Kh5 6.Rf6 c2 7.Rxf5+ Kh6 8.Rf6+ Kg7 9.Rd6 c1Q 10.Rd7+ Kf6 11.Rd6+ Kf7 12.Rxd3 Ke6 13.Ke2 Qb2+ 14.Kf3 Qxh2 (17.259.716) 11063

23.01 0:04 -7.55 1...Rxb2 2.Rxb2 c3 3.Rb6+ Ke7 4.Rb7+ Kd6 5.Rb6+ Kc5 6.Rb8 c2 7.Rc8+ Kd6 8.Rd8+ Ke6 9.e4 c1Q 10.exf5+ Kxf5 11.Rd5+ Ke6 12.Rxd3 Qf1+ 13.Ke4 Qh1+ 14.Rf3 Qxh2 (54.881.696) 12258

24.01 0:05 -7.87 1...Rxb2 2.Rxb2 c3 3.Rb6+ Ke7 4.Rb7+ Kd6 5.Rb6+ Kc5 6.Rb8 c2 7.Rc8+ Kd6 8.Rd8+ Ke6 9.e4 c1Q 10.exf5+ Kxf5 11.Rd5+ Ke6 12.Rxd3 Qf1+ 13.Ke4 Qh1+ 14.Rf3 Qxh2 (71.470.176) 12587

25.01 0:06 -8.16 1...Rxb2 2.Rxb2 c3 3.Rb6+ Ke7 4.Rb7+ Kd6 5.Rb6+ Kc5 6.Rb8 c2 7.Rc8+ Kd6 8.Rd8+ Ke6 9.e4 c1Q 10.exf5+ Kxf5 11.Rd5+ Ke6 12.Rxd3 Qf1+ 13.Ke4 Qh1+ 14.Rf3 Qxh2 (88.514.722) 12867

26.01 0:09 -8.60++ 1...Rxb2 2.Rd1 d2 3.Ke2 c3 4.Rg1 d1N+ 5.Kxd1 Rb1+ 6.Kc2 Rxg1 7.h3 Re1 8.Kxc3 Rxe3+ 9.Kb4 Ke6 10.Kxa4 Rxh3 (127.390.465) 13409

26.01 0:10 -8.60 1...Rxb2 2.Rxb2 c3 3.Rb6+ Ke7 4.Rb7+ Kd6 5.Rb6+ Kc5 6.Rb8 c2 7.Rc8+ Kd6 8.Rd8+ Ke6 9.e4 c1Q 10.exf5+ Kxf5 11.Rd5+ Ke6 12.Rxd3 Qf1+ 13.Ke4 Qh1+ 14.Rf3 Qxh2 (136.748.054) 13423

27.01 0:13 -9.21++ 1...Rxb2 2.Rd1 d2 3.Ke2 c3 4.Rg1 d1N+ 5.Kxd1 Rb1+ 6.Kc2 Rxg1 7.h3 Re1 8.Kxc3 Rxe3+ 9.Kb4 Ke6 10.Kxa4 Rxh3 (179.988.825) 13719

27.01 0:14 -9.21 1...Rxb2 2.Rxb2 c3 3.Rb6+ Ke7 4.Rb7+ Kd6 5.Rb6+ Kc5 6.Rb8 c2 7.Rc8+ Kd6 8.Rd8+ Ke6 9.e4 c1Q 10.exf5+ Kxf5 11.Rd5+ Ke6 12.Rxd3 Qf1+ 13.Ke4 Qh1+ 14.Rf3 Qxh2 (194.228.484) 13757

28.01 0:20 -10.06++ 1...Rxb2 2.Rd1 d2 3.Ke2 c3 4.Rg1 d1N+ 5.Kxd1 Rb1+ 6.Kc2 Rxg1 7.h3 Re1 8.Kxc3 Rxe3+ 9.Kb4 Ke6 10.Kc4 Rxa3 (282.963.010) 14115

28.01 0:26 -10.46 1...Rxb2 2.Rxb2 c3 3.Rb6+ Ke7 4.Rb7+ Kd6 5.Rb6+ Kc5 6.Rb8 c2 7.Rc8+ Kd6 8.Rd8+ Ke6 9.Rxd3 c1Q 10.Ke2 Qb2+ 11.Kf3 Qxh2 12.Rc3 Qh3+ 13.Kf2 Qh4+ 14.Ke2 Qh1 (387.250.910) 14365

29.01 0:41 -12.04++ 1...Rxb2 2.Rd1 d2 3.Ke2 c3 4.Rg1 d1N+ 5.Ke1 Nxe3 6.Rg8 Ng2+ 7.Kd1 Nxf4 8.Rf8+ Ke6 9.Rd8 Ke7 10.Rc8 Rd2+ 11.Kc1 Nd3+ 12.Kb1 Rb2+ 13.Ka1 c2 (605.375.512) 14528

29.01 0:53 -12.40 1...Rxb2 2.Rxb2 c3 3.Rb6+ Ke7 4.Rb7+ Kd6 5.Rb6+ Kc5 6.Rb8 c2 7.Rc8+ Kd6 8.Kf2 d2 9.Rxc2 d1Q 10.Rc8 Qb3 11.Rd8+ Ke7 12.Ra8 Qxa3 13.Ra7+ Ke6 14.Rxh7 Qb2+ (788.246.198) 14633

30.01 1:04 -13.33 1...Rxb2 2.Rxb2 c3 3.Rb6+ Ke7 4.Rb7+ Kd6 5.Rb6+ Kc5 6.Rb8 c2 7.Rc8+ Kd6 8.Kf2 d2 9.Rxc2 d1Q 10.Rc8 Qb3 11.Rd8+ Ke7 12.Ra8 Qxa3 13.Ra7+ Ke6 14.Ke2 Qa2+ (949.161.964) 14710

31.01 1:29 -13.61 1...Rxb2 2.Rxb2 c3 3.Rb6+ Ke7 4.Rb7+ Kd6 5.Rb6+ Kc5 6.Rb8 c2 7.Rc8+ Kd6 8.Rd8+ Ke6 9.Rxd3 c1Q 10.Ke2 Qb2+ 11.Kf3 Qxh2 12.Rc3 Qh1+ 13.Kf2 Qa1 14.Rd3 Qa2+ (1.326.025.290) 14850

32.01 1:44 -14.38++ 1...Rxb2 2.Rd1 d2 3.Ke2 c3 4.Rg1 d1N+ 5.Ke1 Nxe3 6.Rg8 Ng2+ 7.Kd1 Nxf4 8.Rf8+ Ke6 9.Rd8 Ke7 10.Rc8 Rd2+ 11.Kc1 Nd3+ 12.Kb1 Rb2+ 13.Ka1 c2 (1.550.681.044) 14811

32.01 2:03 -15.15++ 1...Rxb2 2.Rd1 d2 3.Ke2 c3 4.Rg1 d1N+ 5.Kxd1 Rb1+ 6.Kc2 Rxg1 7.h3 Re1 8.Kd3 c2 9.Kxc2 Rxe3 10.Kd2 Rxa3 11.h4 h5 12.Ke2 Ke6 13.Kd2 Rb3 14.Kc2 Rf3 (1.838.208.520) 14825

32.01 2:05 -15.15 1...Rxb2 2.Rxb2 c3 3.Rb6+ Ke7 4.Rb7+ Kd6 5.Rb6+ Kc5 6.Rb8 c2 7.Rc8+ Kd6 8.Rd8+ Ke6 9.Rc8 d2 10.Rc6+ Kf7 11.Rxc2 d1Q+ 12.Re2 Ke6 13.h4 Qf1+ 14.Rf2 Qd3 (1.858.181.273) 14809

33.01 2:14 -13.45-- 1...Rxb2 2.Rxb2 c3 3.Rb6+ Ke7 4.Rb7+ Kd6 5.Rb6+ Kc5 6.Rb8 c2 7.Rc8+ Kd6 8.Rd8+ Ke6 9.e4 fxe4+ 10.Kxe4 c1Q 11.f5+ Kf6 12.Rd6+ Kg5 13.Rxd3 Qf4+ 14.Kd5 (2.003.172.061) 14855

33.01 2:43 -16.84++ 1...Rxb2 2.Rxb2 c3 3.Rb6+ Ke7 4.Rb7+ Kd6 5.Rb6+ Kc5 6.Rb8 c2 7.Rc8+ Kd6 8.Rd8+ Ke6 9.e4 fxe4+ 10.Kxe4 c1Q 11.f5+ Kf6 12.Rd6+ Kg5 13.Rxd3 Qf4+ 14.Kd5 Qxh2 (2.416.769.062) 14778

33.01 3:53 -17.65 1...Rxb2 2.Rxb2 c3 3.Rb6+ Ke7 4.Rb7+ Kd6 5.Rb6+ Kc5 6.Rb8 c2 7.Rc8+ Kd6 8.Rd8+ Ke6 9.Rxd3 c1Q 10.Ke2 Qb2+ 11.Kd1 Qxh2 12.Rd2 Qh1+ 13.Ke2 Qa1 14.Rd3 Qb2+ (3.430.147.205) 14709

34.01 6:35 -20.92++ 1...Rxb2 2.Rd1 d2 3.Ke2 c3 4.Rf1 d1Q+ 5.Kxd1 Rb1+ 6.Kc2 Rxf1 7.Kxc3 Rh1 8.h4 Rxh4 9.Kb4 h5 10.Kxa4 Rh1 11.Kb3 h4 12.a4 h3 13.Kb2 Rh2+ 14.Ka3 Re2 (5.723.776.338) 14463

- Matthias Gemuh
**Posts:**3238**Joined:**Thu Mar 09, 2006 8:10 am-
**Contact:**

### Re: WAC.002 by evaluation?

That seems to be by search, not eval.kgburcham wrote: 8/7p/5k2/5p2/p1p2P2/Pr1pPK2/1P1R3P/8 b - -

Stockfish 1.7

22.00 0:01 -5.01 1...Rxb2 2.Rxb2 c3 3.Rb6+ Kg7 4.Rb7+ Kh6 5.Rb6+ Kh5 6.Rf6 c2 7.Rxf5+ Kh6 8.Rf6+ Kg7 9.Rd6 c1Q 10.Rd7+ Kf6 11.Rd6+ Kf7 12.Rxd3 Ke6 13.Ke2 Qb2+ 14.Kf3 Qxh2 (17.259.716) 11063

23.01 0:04 -7.55 1...Rxb2 2.Rxb2 c3 3.Rb6+ Ke7 4.Rb7+ Kd6 5.Rb6+ Kc5 6.Rb8 c2 7.Rc8+ Kd6 8.Rd8+ Ke6 9.e4 c1Q 10.exf5+ Kxf5 11.Rd5+ Ke6 12.Rxd3 Qf1+ 13.Ke4 Qh1+ 14.Rf3 Qxh2 (54.881.696) 12258

Matthias.

My engine was quite strong till I added knowledge to it.

http://www.chess.hylogic.de

http://www.chess.hylogic.de

### Re: WAC.002 by evaluation?

By search (almost) every engine can find it... The question is if there is a program that has good knowledge about connected passed pawns and can find it by eval.

### Re: WAC.002 by evaluation?

This is one of those rules which are expressed "in human terms", but which are strictly not true.metax wrote:A common chess endgame rule says "two connected passers on the sixth beat a rook".

Some exceptions:

a) rook can immediately capture one pawn.

b) rook can fork pawn and king with check

c) defending king can get in front of the pawns (with the aid of discovered check for example)

So it's a search issue anyway.

Joona Kiiski

### Re: WAC.002 by evaluation?

So you think an engine that would implement this rule in its evaluation would give a gross misevaluation in many positions where connected passed pawns play an important role?zamar wrote:This is one of those rules which are expressed "in human terms", but which are strictly not true.metax wrote:A common chess endgame rule says "two connected passers on the sixth beat a rook".

Some exceptions:

a) rook can immediately capture one pawn.

b) rook can fork pawn and king with check

c) defending king can get in front of the pawns (with the aid of discovered check for example)

So it's a search issue anyway.

### Re: WAC.002 by evaluation?

I'd say that exact version of that rule is so complicated that implementing it, is not worth it.metax wrote: So you think an engine that would implement this rule in its evaluation would give a gross misevaluation in many positions where connected passed pawns play an important role?

Joona Kiiski

### Re: WAC.002 by evaluation?

The rule is simply wrong and the program that solve WAC.002 by evaluation will also play Rxb2 in the following position after search of 3 plies Rxb2 Rxb2 c3 because 2 connected passers on the 6th beat a rook.metax wrote:A common chess endgame rule says "two connected passers on the sixth beat a rook". Is there any program that happens to solve WAC.002 by eval?

[D]8/7p/5k2/5p2/p1p2P2/Pr1pPK2/1P1R3P/8 b - -

[D]8/7p/5k2/5p2/p1p2P2/Pr1p1KP1/1P1R3P/8 b - - 0 1

Uri

### Re: WAC.002 by evaluation?

No, because it will see by search that the two connected passers get lost.Uri Blass wrote:The rule is simply wrong and the program that solve WAC.002 by evaluation will also play Rxb2 in the following position after search of 3 plies Rxb2 Rxb2 c3 because 2 connected passers on the 6th beat a rook.metax wrote:A common chess endgame rule says "two connected passers on the sixth beat a rook". Is there any program that happens to solve WAC.002 by eval?

[D]8/7p/5k2/5p2/p1p2P2/Pr1pPK2/1P1R3P/8 b - -

[D]8/7p/5k2/5p2/p1p2P2/Pr1p1KP1/1P1R3P/8 b - - 0 1

Uri

### Re: WAC.002 by evaluation?

It is not going to see it by search if the remaining depth is too smallmetax wrote:No, because it will see by search that the two connected passers get lost.Uri Blass wrote:The rule is simply wrong and the program that solve WAC.002 by evaluation will also play Rxb2 in the following position after search of 3 plies Rxb2 Rxb2 c3 because 2 connected passers on the 6th beat a rook.metax wrote:A common chess endgame rule says "two connected passers on the sixth beat a rook". Is there any program that happens to solve WAC.002 by eval?

[D]8/7p/5k2/5p2/p1p2P2/Pr1pPK2/1P1R3P/8 b - -

[D]8/7p/5k2/5p2/p1p2P2/Pr1p1KP1/1P1R3P/8 b - - 0 1

Uri

and if you do not care about cases when the remaining depth is too small then I do not see why do you need to see it by evaluation.

Uri