White 25

[cheesehead]

Further expansion on[B] [B]25 Bxh6[/B][B] bxc3 26 bxc3 [/B][/B][B]Nxd4[/B]

[B]26 ... Nxd4[/B] after the bxc pawn swap presents stronger problems than if there hadn't been the bxc pawn swap first.

If 27 Ra2 (not 27 Rc1 Ne2+) then ... Ne2+ is prevented but our back rank is unguarded: 27 ... Rb1 28 Rd2 Nb3 29 Rd6 Nf5 oops.

If 27 Ne4 Be5 and then
If 28 Bf4 Ne2+ 28 Kf2 Nxf4 29 gxf4 Bxf4 and Black is up a pawn.
If 28 Be3 Nc2 29 Rc1 Nxe3 30 Nxe3 threatens the c-pawn. (speculation) If ... Ba6 31 Nc5 Rb6 32 Nxa6 Rxa6 33 Nxc4 we're up a pawn but still face a struggle.

If 27 Kf1 or Kf2 prevents ... Ne2+ <== needs more analysis

If 27 ?? <== look at other moves

[B]* * * * * * * *[/B]

[LaurV]

[QUOTE=cheesehead;370142]
[strike]25 Ne3[/strike] bxc3 26 bxc3 Nxd4 and now if 27 cxd4 Bxd4 28 Rc1 Bxc5 29 Rxc4 Bb6 and we're a pawn down, with a pinned knight that prevents Bxh6 (and we must not try 30 Kf1 to relieve the pin because of ... Ba6).
or 25 ... Nxd4 26 cxd4 Bxd4 27 Ne4 Bxb2 28 R-moves c3 and our extra knight has to try coping with the extra three Black pawns -- all passed, two connected.
[/QUOTE]
Whoaaaa... I am back, but it is a lot to go through. I followed up, from the first post up to the fragment quoted above, where I am stuck. I consider Ne3 a good move, as discussed before, and don't agree to strike it out. After bxc3 26 bxc3 Nxd4, we don't need to follow into taking the horse. 27 Nxc4 and we are good, they can't do much with that horse.

Reading/following your further analysis (which again, it is very good btw!).

[cheesehead]

Continuing analysis of [B][B]25 Bxh6 [/B][/B][B][B]bxc3[/B] 2[B]6 bxc3 [/B][/B][B]Nxd4[/B]

Listing all legal moves here:

[strike]27 Ra2[/strike] Rb1 28 Rd2 Nb3 29 Rd6 Nf5 oops.
[strike]27 Ra3[/strike] Rb1 just as bad.
[strike]27 Rb1[/strike] Rxb1
[strike]27 Rc1[/strike] Ne2+
[strike]27 Na6[/strike] Bxa6
[strike]27 Nb3[/strike] Black can capture three ways.
[strike]27 Nb7[/strike] Bxb7
[strike]27 Nd7[/strike] Bxd7
[strike]27 Nxe6[/strike] Bxe6

27 Ne4 Be5 and then
If 28 Bf4 Ne2+ 28 Kf2 Nxf4 29 gxf4 Bxf4 and Black is up a pawn.
If 28 Be3 Nc2 29 Rc1 Nxe3 30 Nxe3 threatens the c-pawn. (speculation) If ... Ba6 31 Nc5 Rb6 32 Nxa6 Rxa6 33 Nxc4 we're up a pawn but still face a struggle.

[strike]27 Nd3[/strike] cxd3
[strike]27 Nb2[/strike] Rxb2
[strike]27 Ne3[/strike] Ne2+ and ... Nxc3
[strike]27 Nf2[/strike] Ne2+ and ... Nxc3
[strike]27 Kf1[/strike] avoids ... Ne2+ but puts King on a6-f1 diagonal. (Future ... Ba6 threat)
[strike]27 Kf2[/strike] avoids ... Ne2+ but leaves King on d4-fork diagonal.
[strike]27 Bh1[/strike] no apparent value
[strike]27 Bf3[/strike] Nxf3+
[strike]27 Be4[/strike] g5 and we can't respond with Ne4
[strike]27 Bd5[/strike] exd5
[strike]27 Bc6+[/strike] Ndxc6
[strike]27 Bb7[/strike] Bxb7
[strike]27 Ba8[/strike] Rxa8
[strike]27 g4[/strike] no apparent value
[strike]27 h3[/strike] no apparent value
[strike]27 h4[/strike] inhibits ... g5 but weakens our King position
[strike]27 Bc1[/strike] Ne2+ and ... Nxc1
[strike]27 Bd2[/strike] retrieves the bishop but doesn't fix our N/d4 problem.

27 Be3 retrieves the bishop and threatens 28 cxd4 or 28 Bxd4 to fix our N/d4 problem <== analyze

[strike]27 Bf4[/strike] Ne2+ and 28 ... Nxf4 29 gxf4 weakens our King position
[strike]27 Bf8[/strike] Kxf8
[strike]27 Bg5[/strike] Bxg5
[strike]27 Bg7[/strike] Bxg7

- - -

As we see above, Be3 is involved in both of the only feasible responses, so is it better right away, or after Ne4?

[B] 27 Be3[/B] allows our N/c5 to stay there for now.
If [B]27 ... Nc2[/B] 28 Rc1 (not Ra2 Rb1) Nxe3 29 Nxe3 and (speculation) if 29 ... Rb2 30 Nxc4 Ra2 31 Nxa5 Bd7 and it's still a struggle. (If 32 Nxd7 Kxd7 our a-pawn is unguarded)
If [B]27 ... Nd5 28 Bxd4 <=analyze [/B]
If [B]27 ... ??[/B]
If [B]27 ... ??[/B]
If [B]27 ... ??[/B]

[B]27 Ne4 Be5[/B] and then
[B]28 Be3[/B] (not 28 Bf4 Ne2+ 28 Kf2 Nxf4 29 gxf4 Bxf4 and Black is up a pawn) Nc2 29 Rc1 Nxe3 30 Nxe3 threatens the c-pawn. (speculation) If ... Ba6 31 Nc5 Rb6 32 Nxa6 Rxa6 33 Nxc4 we're up a pawn but still face a struggle.
I don't see any other helpful move 28 for White in this line.

[cheesehead]

Continuing analysis of [B][B]25 Bxh6 [/B][/B][B][B]bxc3[/B] 2[B]6 bxc3 [/B][/B][B]Nxd4[/B]

Overlooked something in last post:
[QUOTE=cheesehead;370425]< snip >

[B] 27 Be3[/B] allows our N/c5 to stay there for now.
< snip >
If [B]27 ... Nd5 28 Bxd4 <=analyze [/B][/QUOTE]But that just loses a knight for Black (If 28 ... Bxd4+ 29 cxd4 threatening 30 Bxd5 exd5 31 Ne3), so Black won't play 27 ... Nd5.

- - -

That leaves just:
[B][B]25 Bxh6 [/B][/B][B][B]bxc3[/B] 2[B]6 bxc3 [/B][/B][B]Nxd4[/B]

and we move Be3 in both remaining feasible lines. So Be3 first, or after Ne4?

[B]27 Be3[/B] allows our N/c5 to stay there for now.
If [B]27 ... Nc2[/B] 28 Rc1 (not 28 Ra2 Rb1) Nxe3 29 Nxe3 and (speculation) if 29 ... Rb2 30 Nxc4 Ra2 31 Nxa5 Bd7 and it's still a struggle. (If 32 Nxd7 Kxd7 our a-pawn is unguarded against 33 ... Rxa4)
If [B]27 ... Ne2+ 28 Kf2 (or Kf1) Nxc3 29 N1xc3[/B]. We're up a knight for a pawn and can develop our remaining rook off the diagonal running through d4. So Black wouldn't play 27 ... Ne2+
If [B]27 ... ??[/B]
If [B]27 ... ??[/B]

[B]27 Ne4 Be5[/B] and then
[B]28 Be3[/B] (not 28 Bf4 Ne2+ 28 Kf2 Nxf4 29 gxf4 Bxf4 and Black is up a pawn) Nc2 29 Rc1 Nxe3 30 Nxe3 threatens the c-pawn. (speculation) If ... Ba6 31 Nc5 Rb6 32 Nxa6 Rxa6 33 Nxc4 we're up a pawn but still face a struggle.
I don't see any other helpful move 28 for White in this line.

[cheesehead]

Sorry, guys -- there were two serious oversights in my previous post. I guess I didn't realize that I was fatigued.

[QUOTE=cheesehead;370433]< snip >
That leaves just:
[B][B]25 Bxh6 [/B][/B][B][B]bxc3[/B] 2[B]6 bxc3 [/B][/B][B]Nxd4[/B]

and we move Be3 in both remaining feasible lines. So Be3 first, or after Ne4?

[B]27 Be3[/B] allows our N/c5 to stay there for now.
< snip >
If [B]27 ... Ne2+ 28 Kf2 [/B][strike](or Kf1)[/strike][B] Nxc3 29 N1xc3[/B]. [strike]We're up a knight for a pawn[/strike] < snip > [strike]So Black wouldn't play 27 ... Ne2+[/strike][/QUOTE]I mistakenly thought that in this line we'd already played Ne4. Since that invalidated multiple parts of my analysis, I'll just re-state the whole corrected analysis:

[B][B]25 Bxh6 [/B][/B][B][B]bxc3[/B] 2[B]6 bxc3 [/B][/B][B]Nxd4[/B]

and we move Be3 in both remaining feasible lines. So Be3 first, or after Ne4?

[B]27 Be3[/B] allows our N/c5 to stay there for now.
If [B]27 ... Nc2[/B] 28 Rc1 (not 28 Ra2 Rb1) Nxe3 29 Nxe3 and (speculation) if 29 ... Rb2 30 Nxc4 Ra2 31 Nxa5 Bd7 and it's still a struggle. (If 32 Nxd7 Kxd7 our a-pawn is unguarded against 33 ... Rxa4)
If [B]27 ... Ne2+ 28 Kf2 Nxc3 29 Nxc3 Bxc3[/B]. We're down a pawn, but can regain it with [B]30 Rc1 Bb4[/B] (not 30 ... Nd5 31 Bxd5) [B]31 Rxc4[/B]. Now, Black might proceed with 31 ... Bxc5 32 Bxc5 Ba6 33 R-move. (Here we'd be glad we hadn't played 28 Kf1.)

[B]27 Ne4 Be5[/B] and then
[B]28 Be3[/B] (not 28 Bf4 Ne2+ 28 Kf2 Nxf4 29 gxf4 Bxf4 and Black is up a pawn) Nc2 29 Rc1 Nxe3 30 Nxe3 threatens the c-pawn. (speculation) If ... Ba6 31 Nc5 Rb6 32 Nxa6 Rxa6 33 Nxc4 we're up a pawn but still face a struggle.
I don't see any other helpful move 28 for White in this line.

- -

So, maybe we should play [B]27 Ne4[/B] first.

But we'd better look again at that analysis, too -- which I'll do right now.

[B]27 Ne4 Be5[/B]
[B]28 Be3[/B] (not 28 Bf4 Ne2+ 28 Kf2 Nxf4 29 gxf4 Bxf4 and Black is up a pawn)
[B]28 ... Nc2[/B] (not ... Ne2+ 29 Kf2, where Black loses that knight and can get no more than a pawn for it after 29 ... Nxg3 30 hxg3 or 29 ... Nxc3 30 N1xc3 Nd5 31 Rc1)
[B]29 Rc1 Nxe3 30 Nxe3[/B] threatens the c-pawn.
If ... Ba6 31 Nc5 Rb6 32 Nxa6 Rxa6 33 Nxc4 we're up a pawn but still face a struggle.

Is there any other helpful move 28 for White in this line?

If 28 Rc1 Ne2+.

If 28 Bf1 Ba6 29 Nc5 Bc8
If 30 Rc1 Nb3 (not ... Nf3+ 31 Kg2 (not Kf2 Nxh2) Ne1+ 31 Kf2 Nd3+ 32 Nxd3 cxd3 33 Bxd3 we're a pawn up) 31 Nxb3 cxb3 32 Rb1 Bd7 33 Bc4 Bxa4
If 30 Be3 ??

(to be continued)

[cheesehead]

At the end of my previous post, add (after If 28 Bf1 Ba6 29 Nc5 Bc8):

If 30 Bxc4 ??

- -

Capsule opinion: It's looking like [B]25 Bxh6[/B] is feasible. Isolating Black's g-pawn, plus ability of that bishop to snap back to e3, somewhat compensates for our loss of the d-pawn after 25 ... Nxd4.

- -

I'm taking a break.

[LaurV]

Ok, I went superficially through all the analysis. Why superficially and not deeper, is because you wrote a lot, somehow I/you got lost in the details, and it takes too much time. For sure you have a lot of time on your hands.

For me the strategy is clear here: every move that allows them to change the horse for two pawns in the middle is wrong. If they do this, they control the center, have more advanced pawns, our king is not closed enough, their king is not open enough, we can not get more than a draw, if this happens. Playing with two pawns against a horse here, they may even win.

So, the tactic is to forbid them to exchange the horse for two pawns. The only [U]two[/U] (obvious) ways we can go:

(1) 25 Ne3 - if they beat the pawn, we beat the pawn in c4. We are still strong in the center, they can't use that horse for nothing, except eventually Ne2+, with the exchange in c3 from which we exit with advantage.

(2) 25 Ne4 - this is even better, and more aggressive, they can not beat the pawn with the horse (lose the bishop for free) so they will move Bg7, the only way. This allows us to take the other horse out too, 26 Ne3, and now the position really looks better for us now.

[edit: Ne3, in both versions above, also lets us push d5, with double threat, if they make any mistake, like moving something else. We could also exchange woods with Bxc6, but changing woods is not in our advantage now]

There are also some "not so obvious" ways:

(3) 25 Nf2 - apparently they can beat the pawn now, Nxd4, but after 26 Nf2e4, they have two pieces under attack, and Ne2+ with exchange in c3 is not good, because the knight from e4 defends c3 too, so it is lose material for black. The only reasonable black reply is B(e5,g7,h8) and we are good again.

(4) 25 Rc1 - this we discussed it before, the idea was "let them to do the mistake first", here if they get greedy for the d4 pawn, Nxd4, 26 cxd, Bxd4+ 27 Be3, and now we opened the column c for our rook, with heavy artillery support from the two bishops, looks very... black future for black. So, they will not fall for it, but play 25...Nd5 in this situation, most probably, which gives us another tempo, but more defensive compared to version (1) above, where we already have the horses ready to bite.

(5) 25 Be3 - not as good as Ne3, but more direct (i.e. less subtle :smile:), we defend the pawn directly, but lose the defense on c3, this will prompt them to do Nd5 again, most probable (or not, but they can't beat the d4, for sure!) and again, give us another tempo.

All other moves are bad for us. (Especially [B]Bxh6[/B], which was the most analyzed above: after bxc3,bxc3, Nxd4, we can't beat the horse, we have no material advantage, we lost the center, they still have Ne2 threat (then take c3), so the only reasonable move of us seems Ne4, and we can't hope to more than a draw).

Of course, giving a vote right now is hampered by the fact that black can interleave the bxc3 in all of the paths above, making the analysis more difficult, but after some thinking, considering that my time is very limited right now, I will end up here, and go with the aggressive path:

[FONT=Courier New]25 Ne4 - 5 points
25 Ne3 - 3 points
25 Nf2 - 2 points
25 Rc1 - 2 point
25 Be3 - 1 point[/FONT]

other moves: 0 points

[cheesehead]

[QUOTE=LaurV;370474]Ok, I went superficially through all the analysis. Why superficially and not deeper, is because you wrote a lot,[/QUOTE]What I've posted is a "rough draft". I apologize for not having explained that above.

I'll re-post it in cleaner form in a couple of hours.

[quote]somehow I/you got lost in the details[/quote]Not me. Why I wrote all this is so I could go back through without forgetting stuff, without [I]myself[/I] getting lost.

[quote]Of course, giving a vote right now is hampered by the fact that black can interleave the bxc3 in all of the paths above[/quote]I've already added those to my analysis. :-)

[quote]For me the strategy is clear here: every move that allows them to change the horse for two pawns in the middle is wrong.[/quote]I disagree, but your criterion does have the advantage of simplicity.

[quote]If they do this, they control the center, have more advanced pawns, our king is not closed enough, their king is not open enough, we can not get more than a draw, if this happens.[/quote]Wait until you see the cleaner analysis.

We still have positional advantages that allow us more flexibility in employing tactics than Black has. [B]Bxh6[/B] would give us another long-term positional advantage.

[quote]Playing with two pawns against a horse here, they may even win.[/quote]No, we can employ our pieces so as not to allow that.

[quote]So, the tactic is to forbid them to exchange the horse for two pawns.[/quote]I think we can do that.

[quote](Especially [B]Bxh6[/B], which was the most analyzed above:[/quote]The reason I did all that analysis was to show that Black can't get any advantage after Bxh6, and we take advantage of a one-time opportunity to permanently weaken Black's K-side pawns. However, I need to re-post in easier-to-go-through form, when I've sorted out which lines seem best for us.

- - -

In a couple of hours or less, I'll post a cleaner, easier-to-follow analysis, with specific attention to each of your five suggestions.

(to be continued)

[cheesehead]

I'll start off with my analysis of your five suggestions, LaurV.

First, you haven't mentioned (That's okay! I've seen it.) one Black threat after both (1) [B]25 Ne3[/B] and (3) [B]25 Nf2[/B]. Since both of those leave the b2 square unguarded, Black can play [B]25 ... bxc3 26 bxc3 Rb2[/B].
Here, it's better for us if we've played (1) 25 Ne3 than if we've played (3) 25 Nf2:

(1) 25 Ne3 bxc3 26 bxc3 Rb2
Now, 27 Nxc4 both guards our bishop and attacks their rook. Their rook's [I]only[/I] safe move is 27 ... Rb8, back where it came from (if 27 ... Rc2 28 Be4). So, Black will have given us two free tempi to advance our knight from d1 to c4, losing his c-pawn in the process.

But that's not all -- after the rook retreat, we continue with 28 Nd6+ and Black's in big trouble.
I've analyzed past this, but won't post it now because Black probably won't play 26 ... Rb2.

So far, then, (1) 25 Ne3 seems okay ...
[I]except that it does not meet your criterion of preventing Black from sacrificing a knight for two center pawns,

[/I] [strike]25 Ne3[/strike] cxd3 26 cxd3 Nxd4 and now
if 27 cxd4 Bxd4 and we wind up losing a knight and a pawn.
if 27 Nxc4 doesn't save us because of 27 ... Ne2+ 28 K-moves Nxc3 and if 29 Bxc3 Bxc3. So, since move 25, we've captured two black pawns, but Black's captured three white pawns.

- - -

[strike](1) 25 Ne3[/strike] loses us at least a pawn.

(2) [B]25 Ne4[/B] is something I've already analyzed as good, so can stay on the list.

[strike](3) 25 Nf2[/strike] is not adequately ready for Black's threat of 25 ... bxc3 26 bxc3 Rb2.

(4) [B]25 Rc1[/B] also looks okay to me, but not a first choice.

(5) [B]25 Be3[/B]
If [B]25 ... Nd5[/B] we can take with 26 Bxd5, or play
[B]26 Ne4[/B] Bg7 27 Nd6+. After the king moves, we have a choice of either 28 Nxc8 or threat with some other move.
(If 27 ... Kd8 28 Nf7+ and then either 29 Nxh6 or 29 Bxh6)

So, (5) looks okay to me.

- - -

Verdict: your (2), (4) and (5) are okay, but I'll have to look longer to pick my favorite.

- - -

Next, I'll post a cleaned-up version of my analysis of [B]25 Bxh6[/B].

I'm feeling fatigued (because of a medical problem) so it may be longer than two hours until my next post.

(to be continued)

[cheesehead]

[QUOTE=cheesehead;370554] [strike]25 Ne3[/strike] cxd3 26 cxd3 Nxd4 and now[/QUOTE]I meant

[strike]25 Ne3[/strike] bxc3 26 bxc3 Nxd4

[LaurV]

[QUOTE=cheesehead;370546]I disagree, but your criterion does have the advantage of simplicity.
[/QUOTE]

:w00t: strange! because [U]you[/U] put this idea into my mind, and it made roots, hehe, see your posts for the former move, where you "refuted" most of my choices on the reason that black can exchange that horse in the center. After looking deeper into it I reached the conclusion that you were right, therefore now I really believe that we have to avoid that exchange.

[QUOTE=cheesehead;370554]
[strike](1) 25 Ne3[/strike] loses us at least a pawn.
[/QUOTE]

I still don't see how.

[QUOTE]
I'm feeling fatigued (because of a medical problem) so it may be longer than two hours until my next post.
[/QUOTE]Maybe you need some rest. It is just a game. I learned a lot from it, so even if we lose it, no harm done. Just give a summary analysis and your vote. You don't need to write down every possible move, this is pain in the ass for you, and difficult to follow for us. So, take a rest! (time to me to pay your back this advice :razz:, but joking apart, for me it helped!)