So it took me quite a few days just to finish the introduction chapter of Excelling in chess calculation
I was pretty busy lately preparing for uni and cleaning my house, so I'm aiming to pick up the pace now along with other something else every day (endgame, middlegame or opening)
But if the puzzles in this chapter have showed me what's to come, it ain't gonna be easy....
This one left a particularly daunting impression, I was both excited and demoralised doing this puzzle and the calculational difficulties it presented to me, Aargard did say even 2600 would have trouble with it, so I can't feel too bad
This was an endgame study from Yochanan Afek, a well known chess problem composer
It is expected that you don't move a single piece on the board from move 1 to calculate everything
I'll give a demonstration of my thought process and what I still need to improve on.
I saw that 1. b6! is almost necessary and didn't bother to look at other lines like 1. Nc5+ even tho the book briefly mentioned it.
I also thought
1. ... Bf2 was forced and calculated it's variations and didn't look at a few other option which the book also mentioned. Maybe I should've went deeper..
1. ... Bd8 2. Nc5+ Nc8 now b7 isn't available but Bd7#
1. ... Ra7+ (I didn't even consider this) 2. bxa7 Be1+ 3. Kb5 now we can't stop promotion but... f2 4. a8+=Q Kxa8 5. Ka6! making a mating net Qf1+ 6. Bb5 Qf3
7. Bc6+!! WHAT THE F-K Qxc6 8. Nb6+ Kb8 stalemate... as mind blowing as this theme is, I'm pretty sure I've seen quite a few of these in endgame studies.
As disappointed as I am in missing this line, I just have accept I'm not at the level of imagination or visualisation to consider this, even if I've come across a variety of crazy ideas in the endgame
Getting back on track, into the "normal lines"
After 1. b6 Bf2
We have to consider candidates
2. Bb5 Bxb6! 3. Nxb6 Rxa7 0-1 I've seen this
2. Bc6+ Kxc6 3. Ka6 Bxb6 0-1 The book didn't even bother with this line
Now to the ones that the book actually considered:
2. Bd1, 2. Bc2, 2. Bb3
My calculation was quite chaotic and was jumping from line to line trying to compare the difference, but as the book said I should start with
Bd1 the most forcing (hitting f3 straight away)
My calculation:
2. Bd1 Bxb6 3. Nxb6 Rxa7 4. Kb5 (have to stick to knight)
f2 5. Be2 Ra2 (threatening skewer on the b-file)
6. Bf3+ Ka7 7. Nc8 Kb8 wins 0-1
But I missed
5. Bf3+ Kc7 6. Nd5+ Kd6 7. Ne3 I missed this, I thought only of
7. Bg2 Rg7 and black wins but actually this holds...
As you can see we can't go Ka7 because the rook is there where as if
I went 3. f2! back then I would have that Kxa7
So I failed to consider switching the move order with
3. f2 as an alternative to 3. ... Rxa7+ just assuming checking is better because its more forcing, also didn't look at
5. Bf3+ Kxa7! 6. Bg2 Rg8! with Rg5 in mind to win the knight another way!
Now
3. ... f2! 4. Be2 Rxa7 5. Kb5 Ra2 6. Bf3 Ka7!! 7. Bg2 Rg2+ wins the knight 0-1
So Bd1 doesnt work
As i didn't consider 3. ... f2!
all my calculations for 2. Bc2 and 2. Bb3 is flawed because
3. ... f2! kills the 2. Bc2 line whereas the 3. ... Rxa7+ 4. Kb5 f2 5. Be4+ Kc7 6. Nd5+ Kd6 7. Ne3 same idea was above Ke5 8. Bg2 Rg7 9. Bf1 Rg1 10. Kc5!! somehow leads to a line that holds, I have no where considered this far ahead
It's super hard uploading a position for every critical moment of the variations but I hope this picture gives a big of an idea of what the themes are:
That leaves Bb3
It survives the 3. ... f2 line easily because of Bc4 and not being able to be harassed by the rook (try to work that out on the board)
The harder line to calculate
2. Bb3 Bxb6 3. Nxb6 Rxa7! 4. Kb5 f2 5. Bc4 Kc7 6. Nd5+ Kd6 7. Ne3 Rb7+ 8. Ka6! Rb1 9. Bd3 Re1 10. Nf1 Kc6 11. Ka5 Kc5 12. Ka4 Kd4 13. Bb5 Rb1 14. Ng3 Ke3 15. Nf1+ Kf4
BTW
we also have to look at the side line
2. Bb3 Kc6 3. Nb8+ Kc5 4. Na6+ Kc6 5. Bd5+! saccing the bishop to fork! a line I didn't even think of lol
I'm
not sure if you actually need to have this kind of calculation power to reach 2300 (hopefully not, if 2600s can have trouble with this), but I don't care - I don't like doing anything half way and taking on this kind of challenges seem daunting but exciting at the same time...
So since I've been re-enrolled into university, I have to start finishing my degree to the best of my abilities, that means I will have
to self ban for a while from 2p2 when next week begins and
not post for a while. I will still be finishing the calculation books and studying chess tho.