Move 34 discussion: Everyone vs stockfish

[MooMoo2]

The poll for move 33 just closed, and the most popular move was Rxb7. Stockfish responded with 33...Ne5, and the FEN is:
r6k/1R5p/1p3p2/4nN2/8/6P1/P1r4P/R5K1 w - - 1 34

Game so far: 1.e4 e6 2. d4 d5 3. Nd2 c5 4. Ngf3 Nf6 5. exd5 exd5 6. Bb5+ Bd7 7. Bxd7+ Nbxd7 8. O-O Be7 9. dxc5 Nxc5 10. Nb3 Nce4 11. Nfd4 O-O 12. Nf5 Re8 13. Nxe7+ Rxe7 14. f3 Nd6 15. Bg5 Nc4 16. Bxf6 gxf6 17. Qd4 Qb6 18. Qxb6 axb6 19. Rfd1 Re5 20. f4 Re2 21. Nd4 Re4 22. Nf5 Nxb2 23. Rxd5 Rxf4 24. g3 Rc4 25. Nh6+ Kg7 26. Nf5+ Kf8 27. Rd7 Rxc2 28. Nh6 Kg7 29. Nf5+ Kg6 30. Nh4+ Kg7 31. Nf5+ Kh8 32. Rxf7 Nd3 33. Rxb7 Ne5

[Brian-E]

34.Rf1 and 34.h4 were both mentioned last move as a method of dealing with the threat of ...Nf3+ picking up our h pawn.

I'm just wondering now if the more active 34.Rd1 is worth considering. I think we end up a pawn down, but provided that we eliminate Black's dangerous b pawn then a position with Black having just h and blockaded f pawn against our g pawn is drawn if both our rooks are active. For example 34.Rd1 Nf3+ 35.Kf1 Nxh2+ 36.Kg1 Nf3+ 37.Kf1 Rd2 (or 37...Ne5 38.Rxb6) 38.Rc1 Rdxa2 39.Rxb6 (not of course 39.Rcc7?? Rh2). If our opponent did not happen to be an engine rated over 3300 I would be confident of drawing this position.

But then again, why go for a position a pawn down if it is unnecessary? I think I'm currently still inclined towards 34.Rf1.

[WMHalsdorf]

In the interest of having to choose.

34.Nh4 Rcxa2 35.35.Rxa2 Rxa2 36.Rxb6

34.Rf1 h5 35.Rxb6 Raxa2 36.Nh4 Rxh2 37.Rbxf6

[The Carnivore]

Originally Posted by Brian-E

I think we end up a pawn down, but provided that we eliminate Black's dangerous b pawn then a position with Black having just h and blockaded f pawn against our g pawn is drawn if both our rooks are active.

Is there anything wrong with taking Black's b-pawn now with Rxb6?

[R. Gerbicz]

Originally Posted by The Carnivore

Is there anything wrong with taking Black's b-pawn now with Rxb6?

Not very good, I see the following line:
34 Rxb6 Nf3+ 35 Kf1 (Kh1? Rxh2 mate) Rxh2 36 Rb1 Nd2+
and black would be in exchange up position.

EDIT: or better we could go to a threefold repition with 37 Kg1 Nd2 etc.

[WMHalsdorf]

Originally Posted by R. Gerbicz

Not very good, I see the following line:
34 Rxb6 Nf3+ 35 Kf1 (Kh1? Rxh2 mate) Rxh2 36 Rb1 Nd2+
and black would be in exchange up position.

EDIT: or better we could go to a threefold repition with 37 Kg1 Nd2 etc.

35...Nxh2 36.Kg1 (Ke1 loses t0 Re8+) Nf3+

[Brian-E]

Gary wrote the following last move concerning the possibility 34.Rxb6:

Originally Posted by gd_barnes

On another note, I do not think that the swap with 33. Rxb7 Ne5 34. Rxb6 Nf3+ 35. Kf1 Nxh2+ 36. Nf3+ Kf1 would be good. We are likely to have difficulty protecting our a-pawn in the end game whereas black can easily guard his two pawns with his king and knight. We are better to swap off our a-pawn for his b-pawn at some point if it comes down to that.

My own opinion is that 34.Rxb6 is definitely worth considering. If we end up losing the a pawn (as well as the h pawn) I regard the endgame as probably drawn. We should note that with a pure rook endgame, the defending side would draw against an f pawn and an h pawn even without our own g pawn. The presence of an extra rook and a knight each complicates that, but if Black has no mating attack then I still think it's drawn.

[LaurV]

There is some king move missing there at 36. Just nitpicking, we got the idea...

[richs]

34. Rf1 and we'll see how SF responds. I see why SF rejected our offer of a draw; Black still has game....

[gd_barnes]

Originally Posted by WMHalsdorf

In the interest of having to choose.

34.Nh4 Rcxa2 35.35.Rxa2 Rxa2 36.Rxb6

34.Rf1 h5 35.Rxb6 Raxa2 36.Nh4 Rxh2 37.Rbxf6

Excellent analysis!

Some additional analysis for Nh4:
34.Nh4 Rcxa2 35.35.Rxa2 Rxa2 36.Rxb6 Kg7 37. h3 h5
It's probably drawn but black's position is somewhat better. He is able to advance his pawns further and move his king towards the center before we can. It feels a little tougher for us than it needs to be. The fact that he can advance his king to g7 before we can pin it on its first rank helps him whereas our king is stuck.

A slight change for Rf1:
34.Rf1 h5 35.Rxb6 Raxa2 36. Rb8+ Kh7 37. Rb7+ Kh8 (or Kg8) [not 37...Kg6 38. Rg7 mate] 38. Nh4
Two lines from here:
First, effectively the one that you suggested (except that our rook is at b7 instead of b6):
38...Rxh2 39. Rxf6 Rhd2 40. Rf1
Black has no way to progress further because we threaten perpetual check.
Second:
38...Ng4 39. Rd1!* (threatening mate)
Now black has to play Ra8, Rc8, or Rd2 and so can make no progress.

* The subtlety of the two seemingly meaningless checks (shown in red) by us leaves black in effectively the same position but puts our rook on black's 2nd rank (vs. 3rd), something that comes into play here and likely in other variations.

34. Rf1 looks like the best move! I'm curious to see if SF has anything unexpected up his sleeve if we make this move. It feels like he has to unpin his rook by playing h5.

[WMHalsdorf]

Originally Posted by gd_barnes

Excellent analysis!

Some additional analysis for Nh4:
34.Nh4 Rcxa2 35.35.Rxa2 Rxa2 36.Rxb6 Kg7 37. h3 h5
It's probably drawn but black's position is somewhat better. He is able to advance his pawns further and move his king towards the center before we can. It feels a little tougher for us than it needs to be. The fact that he can advance his king to g7 before we can pin it on its first rank helps him whereas our king is stuck.

A slight change for Rf1:
34.Rf1 h5 35.Rxb6 Raxa2 36. Rb8+ Kh7 37. Rb7+ Kh8 (or Kg8) [not 37...Kg6 38. Rg7 mate] 38. Nh4
Two lines from here:
First, effectively the one that you suggested (except that our rook is at b7 instead of b6):
38...Rxh2 39. Rxf6 Rhd2 40. Rf1
Black has no way to progress further because we threaten perpetual check.
Second:
38...Ng4 39. Rd1!* (threatening mate)
Now black has to play Ra8, Rc8, or Rd2 and so can make no progress.

* The subtlety of the two seemingly meaningless checks (shown in red) by us leaves black in effectively the same position but puts our rook on black's 2nd rank (vs. 3rd), something that comes into play here and likely in other variations.

34. Rf1 looks like the best move! I'm curious to see if SF has anything unexpected up his sleeve if we make this move. It feels like he has to unpin his rook by playing h5.

Nice expansion of the lines.