analysis of 1.e4 e5 2.Nf3 f6

Discussion of anything and everything relating to chess playing software and machines.

Moderators: hgm, Harvey Williamson, bob

Forum rules
This textbox is used to restore diagrams posted with the [d] tag before the upgrade.
acase
Posts: 653
Joined: Wed Mar 15, 2006 12:14 am
Location: Columbus, Ohio USA

Re: analysis of 1.e4 e5 2.Nf3 f6

Post by acase » Sun Aug 12, 2018 11:25 pm

Looks like Stockfish doesn't change it's mind after 60+ plys it still likes 3.Nf3xe5 and the eval doeasn't really change either:


Stockfish_18080817_x64_bmi2:

56/84 12:48:05 1,152,343,267k 25,004k +1.82 3.Nf3xe5 Qd8-e7 4.Ne5-f3 d7-d5 5.d2-d3 Nb8-c6 6.Nb1-c3 Bc8-e6 7.Bc1-e3 d5xe4 8.d3xe4 a7-a6 9.Nc3-d5 Qe7-d7 10.c2-c4 Bf8-b4+ 11.Nd5xb4 Qd7xd1+ 12.Ra1xd1 Nc6xb4 13.Nf3-d4 Be6-d7 14.a2-a3 Nb4-c6 15.Nd4xc6 Bd7xc6 16.f2-f3 Ng8-e7 17.Be3-f4 Ra8-c8 18.Bf1-e2 Ke8-f7 19.Bf4-g3 Rh8-e8 20.b2-b4 Bc6-a4 21.Rd1-d2 h7-h5 22.h2-h4 Ne7-g6 23.Ke1-f2 Ng6-e5 24.Kf2-e3 Rc8-d8 25.Rd2-d5 Ba4-c6 26.Rd5xd8 Re8xd8 27.b4-b5 Bc6-e8 28.a3-a4 Kf7-e7 29.b5xa6 b7xa6 30.Rh1-b1 Be8xa4 31.Rb1-a1 Ba4-b3 32.Bg3xe5 f6xe5 33.Ra1-a5 Ke7-e6 34.Ra5xa6+ Rd8-d6 35.Ra6-a7 Ke6-d7 36.c4-c5
57/76+ 13:03:16 1,175,489,147k 25,012k +1.89 3.Nf3xe5
57/76+ 14:50:34 1,337,490,139k 25,030k +1.97 3.Nf3xe5
57/78 15:38:47 1,409,756,668k 25,028k +1.86 3.Nf3xe5 Qd8-e7 4.Ne5-f3 d7-d5 5.d2-d3 Nb8-c6 6.Nb1-c3 Bc8-e6 7.Bc1-e3 d5xe4 8.d3xe4 a7-a6 9.Nc3-d5 Qe7-d7 10.c2-c4 Bf8-b4+ 11.Nd5xb4 Qd7xd1+ 12.Ra1xd1 Nc6xb4 13.Nf3-d4 Be6-d7 14.a2-a3 Nb4-c6 15.Nd4xc6 Bd7xc6 16.f2-f3 Ng8-e7 17.Bf1-e2 Ne7-g6 18.b2-b4 Ng6-e5 19.h2-h3 O-O 20.Rd1-d4 Ra8-d8 21.Ke1-f2 Bc6-a4 22.Rh1-c1 Rf8-e8 23.Rd4-d5 Ba4-c6 24.Rd5-d2 Bc6-a4 25.h3-h4 Rd8xd2 26.Be3xd2 Re8-d8 27.Kf2-e3 h7-h5 28.Bd2-c3 Kg8-f7 29.Rc1-f1 Kf7-e6 30.g2-g3 Rd8-h8 31.Rf1-b1 Rh8-d8 32.Rb1-c1 g7-g6 33.Bc3-b2 Ke6-f7 34.Bb2xe5 f6xe5 35.f3-f4 Kf7-f6 36.b4-b5 a6xb5 37.c4xb5
58/82- 21:22:58 1,926,744,090k 25,030k +1.79 3.Nf3xe5 Qd8-e7
58/82+ 21:26:34 1,932,187,107k 25,030k +1.86 3.Nf3xe5
58/82 22:07:09 1,992,935,956k 25,028k +1.89 3.Nf3xe5 Qd8-e7 4.Ne5-f3 d7-d5 5.d2-d3 Bc8-e6 6.Bc1-e3 Nb8-c6 7.Nb1-c3 d5xe4 8.d3xe4 a7-a6 9.Nc3-d5 Qe7-d7 10.c2-c4 Bf8-b4+ 11.Nd5xb4 Qd7xd1+ 12.Ke1xd1 Nc6xb4 13.Kd1-d2 Nb4-c6 14.Kd2-c3 Ng8-h6 15.Bf1-e2 Be6-d7 16.Nf3-d4 a6-a5 17.Nd4xc6 Bd7xc6 18.f2-f3 Nh6-f7 19.b2-b3 O-O-O 20.Be3-d4 b7-b6 21.h2-h4 Rh8-e8 22.Rh1-e1 Rd8-d7 23.Ra1-d1 h7-h5 24.Bd4-f2 Nf7-e5 25.Rd1xd7 Kc8xd7 26.a2-a4 Re8-b8 27.Bf2-d4 Kd7-e6 28.f3-f4 Ne5-g4 29.g2-g3 Ke6-f7 30.c4-c5 b6-b5 31.Be2xb5 Bc6xb5 32.a4xb5 Rb8xb5 33.Re1-a1 Kf7-e8 34.c5-c6
59/91- 22:46:49 2,052,610,985k 25,029k +1.82 3.Nf3xe5 Qd8-e7
59/91+ 23:16:30 2,097,400,175k 25,031k +1.89 3.Nf3xe5
59/91 31:02:34 2,805,146,823k 25,101k +1.90 3.Nf3xe5 Qd8-e7 4.Ne5-f3 d7-d5 5.d2-d3 d5xe4 6.d3xe4 Qe7xe4+ 7.Bf1-e2 Nb8-c6 8.Nb1-c3 Qe4-e6 9.O-O Bc8-d7 10.Bc1-f4 O-O-O 11.Nc3-b5 Nc6-e5 12.Nb5xa7+ Kc8-b8 13.Na7-b5 Bf8-c5 14.b2-b4 Bc5-b6 15.a2-a4 Ng8-e7 16.Qd1-c1 Ne7-g6 17.Nf3-d4 Bb6xd4 18.Nb5xd4 Ng6xf4 19.Qc1xf4 Qe6-d5 20.Rf1-d1 Ne5-c6 21.Nd4xc6+ Qd5xc6 22.b4-b5 Qc6-c5 23.c2-c4 Rh8-e8 24.Be2-f1 Bd7-c8 25.a4-a5 Qc5-g5 26.Qf4xg5 f6xg5 27.Rd1xd8 Re8xd8 28.Ra1-e1 g5-g4 29.f2-f3 g4xf3 30.g2xf3 g7-g6 31.Re1-e7 h7-h5 32.h2-h4 Rd8-d4 33.Re7-e4 Rd4-d8 34.Kg1-f2 Bc8-f5 35.Re4-e7 Kb8-c8 36.c4-c5 Rd8-d2+ 37.Kf2-g3 Rd2-a2 38.b5-b6 c7xb6 39.a5xb6 Ra2-c2
60/79- 37:29:07 3,393,453,058k 25,146k +1.83 3.Nf3xe5 Qd8-e7
60/79+ 39:30:27 3,575,011,313k 25,136k +1.90 3.Nf3xe5
60/80- 46:25:25 4,194,100,516k 25,096k +1.75 3.Nf3xe5 Qd8-e7
60/80 46:46:07 4,225,097,404k 25,095k +1.78 3.Nf3xe5 Qd8-e7 4.Ne5-f3 d7-d5 5.d2-d3 Nb8-c6 6.Nb1-c3 Bc8-e6 7.Bc1-e3 d5xe4 8.d3xe4 Qe7-d7 9.Bf1-b5 a7-a6 10.Bb5xc6 Qd7xc6 11.Nf3-d4 Qc6-d7 12.Nd4xe6 Qd7xe6 13.Qd1-h5+ g7-g6 14.Qh5-d5 Qe6xd5 15.Nc3xd5 O-O-O 16.O-O-O Rd8-e8 17.f2-f3 Re8-e6 18.Be3-d4 Bf8-d6 19.h2-h4 h7-h5 20.c2-c4 Rh8-h7 21.b2-b4 Rh7-f7 22.c4-c5 Bd6-e5 23.Bd4xe5 Re6xe5 24.Nd5-f4 Ng8-e7 25.Nf4-d3 Re5-e6 26.Kc1-c2 Ne7-c6 27.Kc2-c3 Re6-e8 28.a2-a4 f6-f5 29.Nd3-f2 f5xe4 30.Nf2xe4 Re8-e7 31.Rd1-d2 Re7-d7 32.Rh1-d1 Rd7xd2 33.Rd1xd2 Rf7-d7 34.Rd2xd7 Kc8xd7
61/86- 59:27:17 5,366,591,580k 25,073k +1.71 3.Nf3xe5 Qd8-e7
61/86+ 59:41:11 5,387,817,313k 25,075k +1.78 3.Nf3xe5
61/87+ 60:56:00 5,501,065,843k 25,078k +1.90 3.Nf3xe5
61/98 88:26:35 8,004,877,604k 25,141k +1.79 3.Nf3xe5 Qd8-e7 4.Ne5-f3 d7-d5 5.d2-d3 Bc8-e6 6.Nb1-c3 Nb8-c6 7.Bc1-e3 d5xe4 8.d3xe4 Qe7-d7 9.Bf1-b5 a7-a6 10.Bb5xc6 Qd7xc6 11.Nf3-d4 Qc6-d7 12.Nd4xe6 Qd7xe6 13.Qd1-h5+ g7-g6 14.Qh5-d5 Qe6xd5 15.Nc3xd5 O-O-O 16.O-O-O Rd8-e8 17.f2-f3 Re8-e6 18.h2-h4 Bf8-h6 19.h4-h5 Bh6xe3+ 20.Nd5xe3 g6-g5 21.Rd1-d4 Ng8-e7 22.Rh1-d1 Ne7-c6 23.Rd4-d5 Re6-e7 24.b2-b3 Nc6-e5 25.Kc1-d2 Re7-d7 26.Kd2-e2 Rh8-d8 27.Rd5xd7 Ne5xd7 28.c2-c4 Rd8-e8 29.Ke2-f2 a6-a5 30.Ne3-g4 Re8-e6 31.Kf2-g3 c7-c6 32.Ng4-e3 b7-b6 33.Kg3-g4 Kc8-c7 34.h5-h6 Re6-d6 35.Kg4-f5 Rd6xd1 36.Ne3xd1 Kc7-d6 37.Nd1-f2 Kd6-e7 38.Nf2-d3
62/83+ 89:30:52 8,102,750,598k 25,144k +1.86 3.Nf3xe5

Karol Majewski
Posts: 85
Joined: Sat Jul 09, 2011 2:18 pm

Re: analysis of 1.e4 e5 2.Nf3 f6

Post by Karol Majewski » Mon Aug 13, 2018 7:50 am

So it seems that the main goes like: 1.e4 e5 2.Nf3 f6 3.Nxe5 Qe7 4.Nf3 d5 5.d3 and now black has a choice:
5...dxe4 6.dxe4 Qxe4
5...Nc6
5...Be6

So if we want to refute the opening - and I belive that there is a refutation - we should analyse these three positions to a great depth.

Note that after 5...dxe4 6.dxe4 Qxe4 it's not that obvious that 7.Be2 is the best cause there is also 7.Be3.

zullil
Posts: 4936
Joined: Mon Jan 08, 2007 11:31 pm
Location: PA USA
Full name: Louis Zulli

Re: analysis of 1.e4 e5 2.Nf3 f6

Post by zullil » Mon Aug 13, 2018 11:19 am

Karol Majewski wrote:
Mon Aug 13, 2018 7:50 am
So it seems that the main goes like: 1.e4 e5 2.Nf3 f6 3.Nxe5 Qe7 4.Nf3 d5 5.d3 and now black has a choice:
5...dxe4 6.dxe4 Qxe4
5...Nc6
5...Be6

So if we want to refute the opening - and I belive that there is a refutation - we should analyse these three positions to a great depth.

Note that after 5...dxe4 6.dxe4 Qxe4 it's not that obvious that 7.Be2 is the best cause there is also 7.Be3.
How much of a refutation do you want after two moves?! An evaluation of +1.86 (which must include SF's default contempt) certainly suggests that this defense sucks. :shock:

In any case, I'm searching the position below, just to confirm that SF-dev prefers 7.Be2.


Karol Majewski
Posts: 85
Joined: Sat Jul 09, 2011 2:18 pm

Re: analysis of 1.e4 e5 2.Nf3 f6

Post by Karol Majewski » Mon Aug 13, 2018 11:47 am

zullil wrote:
Mon Aug 13, 2018 11:19 am
Karol Majewski wrote:
Mon Aug 13, 2018 7:50 am
So it seems that the main goes like: 1.e4 e5 2.Nf3 f6 3.Nxe5 Qe7 4.Nf3 d5 5.d3 and now black has a choice:
5...dxe4 6.dxe4 Qxe4
5...Nc6
5...Be6

So if we want to refute the opening - and I belive that there is a refutation - we should analyse these three positions to a great depth.

Note that after 5...dxe4 6.dxe4 Qxe4 it's not that obvious that 7.Be2 is the best cause there is also 7.Be3.
How much of a refutation do you want after two moves?! An evaluation of +1.86 (which must include SF's default contempt) certainly suggests that this defense sucks. :shock:

In any case, I'm searching the position below, just to confirm that SF-dev prefers 7.Be2.

I get your point Louis but there is a difference between 'much worse' and 'lost'. It's clear that black is much worse here but is he lost? This is what Uri asked in the first post, I belive. There are many opening positions where engine gives +1.80 and later it occurs that it's not possible to convert this adventage into win.

whereagles
Posts: 513
Joined: Thu Nov 13, 2014 11:03 am

Re: analysis of 1.e4 e5 2.Nf3 f6

Post by whereagles » Mon Aug 13, 2018 11:56 am

the opening is refuted for practical purposes.

if other lines (ruy lopez, petroff, etc.) give black 0.40, why would black hasten to a 1.80 score? :D

Karol Majewski
Posts: 85
Joined: Sat Jul 09, 2011 2:18 pm

Re: analysis of 1.e4 e5 2.Nf3 f6

Post by Karol Majewski » Mon Aug 13, 2018 12:05 pm

whereagles wrote:
Mon Aug 13, 2018 11:56 am
the opening is refuted for practical purposes.

if other lines (ruy lopez, petroff, etc.) give black 0.40, why would black hasten to a 1.80 score? :D
If Ruy Lopez and Petroff give black 0.40 then why people keep playing the king's gambit 2.f4? Again, after 2.f4 white is much worse but is he lost? We don't know it yet.

zullil
Posts: 4936
Joined: Mon Jan 08, 2007 11:31 pm
Location: PA USA
Full name: Louis Zulli

Re: analysis of 1.e4 e5 2.Nf3 f6

Post by zullil » Mon Aug 13, 2018 12:39 pm

Karol Majewski wrote:
Mon Aug 13, 2018 11:47 am


I get your point Louis but there is a difference between 'much worse' and 'lost'. It's clear that black is much worse here but is he lost? This is what Uri asked in the first post, I belive. There are many opening positions where engine gives +1.80 and later it occurs that it's not possible to convert this adventage into win.

SF-dev with default contempt:

+1.98 7. Be2 Bb4+ 8. c3 Bd6 9. O-O Ne7 10. Nbd2 Qg6 11. Re1 O-O 12. Nd4 Nbc6 13. Bh5 Qd3 14. Re3 Qa6 15. Be2 Qa5 16. b4 Qg5 17. Nxc6 Nxc6 18. Ne4 Qf5 19. Nxd6 cxd6 20. Qxd6 Ne5 21. f4 Nf7 22. Qc7 Qd7 23. Re7 Qxc7 24. Rxc7 Re8 25. Bh5 g6 26. Bf3 Nd6 27. c4 Be6 28. Bb2 Rac8 29. Rxc8 Bxc8 30. c5 Ne4 31. Rd1 f5 32. Be5 Kf7 33. a4 a5 34. bxa5 Nxc5 35. Rc1 Nd3 36. Rc7+ Ke6 37. Rxh7 Nxe5 38. fxe5 Rd8 39. Bxb7 Bxb7 40. Rxb7 Rd4 41. Rb6+ Kxe5 (depth 51, 2:22:03)

I'll let this go futher, but +1.98 seems pretty close to "won". :D

whereagles
Posts: 513
Joined: Thu Nov 13, 2014 11:03 am

Re: analysis of 1.e4 e5 2.Nf3 f6

Post by whereagles » Mon Aug 13, 2018 3:13 pm

Karol Majewski wrote:
Mon Aug 13, 2018 12:05 pm
If Ruy Lopez and Petroff give black 0.40 then why people keep playing the king's gambit 2.f4? Again, after 2.f4 white is much worse but is he lost? We don't know it yet.
We play the king's gambit because it's fun. The damiano doesn't seem like fun at all. More like masochism :D

zullil
Posts: 4936
Joined: Mon Jan 08, 2007 11:31 pm
Location: PA USA
Full name: Louis Zulli

Re: analysis of 1.e4 e5 2.Nf3 f6

Post by zullil » Mon Aug 13, 2018 4:50 pm

zullil wrote:
Mon Aug 13, 2018 12:39 pm
Karol Majewski wrote:
Mon Aug 13, 2018 11:47 am


I get your point Louis but there is a difference between 'much worse' and 'lost'. It's clear that black is much worse here but is he lost? This is what Uri asked in the first post, I belive. There are many opening positions where engine gives +1.80 and later it occurs that it's not possible to convert this adventage into win.

SF-dev with default contempt:

+1.98 7. Be2 Bb4+ 8. c3 Bd6 9. O-O Ne7 10. Nbd2 Qg6 11. Re1 O-O 12. Nd4 Nbc6 13. Bh5 Qd3 14. Re3 Qa6 15. Be2 Qa5 16. b4 Qg5 17. Nxc6 Nxc6 18. Ne4 Qf5 19. Nxd6 cxd6 20. Qxd6 Ne5 21. f4 Nf7 22. Qc7 Qd7 23. Re7 Qxc7 24. Rxc7 Re8 25. Bh5 g6 26. Bf3 Nd6 27. c4 Be6 28. Bb2 Rac8 29. Rxc8 Bxc8 30. c5 Ne4 31. Rd1 f5 32. Be5 Kf7 33. a4 a5 34. bxa5 Nxc5 35. Rc1 Nd3 36. Rc7+ Ke6 37. Rxh7 Nxe5 38. fxe5 Rd8 39. Bxb7 Bxb7 40. Rxb7 Rd4 41. Rb6+ Kxe5 (depth 51, 2:22:03)

I'll let this go futher, but +1.98 seems pretty close to "won". :D
+2.08 7. Be2 Bd6 8. Nc3 Qe6 9. Nd4 Qd7 10. Ndb5 Be5 11. O-O Qxd1 12. Rxd1 Na6 13. f4 Bxc3 14. bxc3 f5 15. Re1 Nf6 16. Bc4+ Ne4 17. Bd5 Kd8 18. Ba3 Nac5 19. Rad1 Bd7 20. Nd4 Kc8 21. Bxc5 Nxc5 22. Re7 g6 23. Nb3 Nxb3 24. cxb3 a5 25. Bxb7+ Kxb7 26. Rdxd7 Rac8 27. Rxh7 Rxh7 28. Rxh7 Rd8 29. h4 Rd1+ 30. Kh2 Rf1 31. Kg3 a4 32. bxa4 Rc1 33. Rg7 Rxc3+ 34. Kf2 Rc6 35. g4 Rc2+ 36. Ke3 fxg4 37. Rxg6 Rxa2 38. h5 Rxa4 39. Rxg4 (depth 54, 5:39:05)

Karol Majewski
Posts: 85
Joined: Sat Jul 09, 2011 2:18 pm

Re: analysis of 1.e4 e5 2.Nf3 f6

Post by Karol Majewski » Mon Aug 13, 2018 5:35 pm

zullil wrote:
Mon Aug 13, 2018 4:50 pm
zullil wrote:
Mon Aug 13, 2018 12:39 pm
Karol Majewski wrote:
Mon Aug 13, 2018 11:47 am


I get your point Louis but there is a difference between 'much worse' and 'lost'. It's clear that black is much worse here but is he lost? This is what Uri asked in the first post, I belive. There are many opening positions where engine gives +1.80 and later it occurs that it's not possible to convert this adventage into win.

SF-dev with default contempt:

+1.98 7. Be2 Bb4+ 8. c3 Bd6 9. O-O Ne7 10. Nbd2 Qg6 11. Re1 O-O 12. Nd4 Nbc6 13. Bh5 Qd3 14. Re3 Qa6 15. Be2 Qa5 16. b4 Qg5 17. Nxc6 Nxc6 18. Ne4 Qf5 19. Nxd6 cxd6 20. Qxd6 Ne5 21. f4 Nf7 22. Qc7 Qd7 23. Re7 Qxc7 24. Rxc7 Re8 25. Bh5 g6 26. Bf3 Nd6 27. c4 Be6 28. Bb2 Rac8 29. Rxc8 Bxc8 30. c5 Ne4 31. Rd1 f5 32. Be5 Kf7 33. a4 a5 34. bxa5 Nxc5 35. Rc1 Nd3 36. Rc7+ Ke6 37. Rxh7 Nxe5 38. fxe5 Rd8 39. Bxb7 Bxb7 40. Rxb7 Rd4 41. Rb6+ Kxe5 (depth 51, 2:22:03)

I'll let this go futher, but +1.98 seems pretty close to "won". :D
+2.08 7. Be2 Bd6 8. Nc3 Qe6 9. Nd4 Qd7 10. Ndb5 Be5 11. O-O Qxd1 12. Rxd1 Na6 13. f4 Bxc3 14. bxc3 f5 15. Re1 Nf6 16. Bc4+ Ne4 17. Bd5 Kd8 18. Ba3 Nac5 19. Rad1 Bd7 20. Nd4 Kc8 21. Bxc5 Nxc5 22. Re7 g6 23. Nb3 Nxb3 24. cxb3 a5 25. Bxb7+ Kxb7 26. Rdxd7 Rac8 27. Rxh7 Rxh7 28. Rxh7 Rd8 29. h4 Rd1+ 30. Kh2 Rf1 31. Kg3 a4 32. bxa4 Rc1 33. Rg7 Rxc3+ 34. Kf2 Rc6 35. g4 Rc2+ 36. Ke3 fxg4 37. Rxg6 Rxa2 38. h5 Rxa4 39. Rxg4 (depth 54, 5:39:05)
Seems we're getting there :)

Post Reply