f5 wins, if Rf5 then Rg1+ and black queens. Black needs an f pawn to play f3+ as this will force the white king from the safe squares of g2 and h2 to take the pawn this allows Rf1+ and a1+q. if Kf2 Rh1 wins the rook after Ra2 Rh2+ and Ra2 or black queens the a pawn. A very valuable rook and pawn endgame from Susan.
Well, there are several options for black-king moveslike Kh4, Kg4, Kh6, Kg6, and the pawn move f5. Of course, we can eliminate all the possible rook moves due to white playing Ra2. I guess my first real thought in this position is, “Can I get the king over to b3 to support the pawn?” However, my experience tells me that long range rook checks from white will make this a hopeless task. At this point, I don’t have a plan to just jumps out at me. The white rook can’t leave the a-file without delivering check, otherwise black moves his rook laterally and forces white to sacrifice his rook for the pawn. The white king cannot advance to the third rank without allowing a rook check from black that again forces the exchange of the white rook for the a-pawn. I am more or less forced to consider each possible line separately and see if I can learn anything from the resulting positions:
Option A with 1. ….Kg4:
This is the move that looks most “natural” to me, but I already suspect it sucks for exactly that reason:
7. …..g4 (what else to try?) 8. Rc8 Kb3 9. Rb8 and, white can check with impunity from the 8th rank, and if the black king tries walking him down, the white rook returns to a3. At move 3 above, I don’t think black can do any better with
3. …..Kh5 4. Ra5 Kh4 5. Ra4 g4 6. Ra5 g3 (Rd1 7.Ra2=) 7. Ra3 Kh5(Kg4 or Kg5 8.Rg3+) 8. Ra5 and we have almost the same position as before- the white king cannot be used to support the a-pawn without endless long distance checks from the white rook.
Option B with 1. ….Kh4:
I suspect this move is no better than Kg4.
1. …..Kh4 2. fg5 fg5 3. Ra4 and there is no need to go further with this as it is same type of dry draw as we have already seen.
Option C with 1. ….Kg6:
1. …..Kg6 2. fg5 f5 (fg5 like lines above)
Now, this does look different than the lines above. At some point black can play f3 with check. This may not seem important, but it does offer black the opportunity to play Rh1 should the white king move to f2- the point being that Ra2 is answered by Rh2+ X-raying white’s rook. Continuing:
And, now, black is threatening f3. White can continue to check from the a-file for two more moves:
8. Ra4 Ke3 9. Ra3 Ke2
And white is in zugzwang. There are two basic options for white- Ra6-8 or Kh2:
10.Ra8 f3+ 11.Kh2 f2 12.Re8 Kd3
And black will walk the white rook down traveling up the e and d-files until he forces the rook to move away for a move just long enough to queen the f-pawn. At move 11 in this line, white still loses with
11.Kg3 Rg1 12.Kh2 a1(Q) At move 10, white still loses with
10.Kh2 f3 11.Ra8 f2 and we transpose into the lines above in which black walks the white rook down on the 8th rank. In this line, the only other option seems to arise at move 2. From the top:
And white is in zugzwang again- either lose the f5 pawn or move the king to h2 or f2. Losing f5 loses the game as black will win easily by pushing the connected pawns:
6. Kf2 Rh1 7. Ra4 Kf5 and black wins. Or
6. Kh2 Kf3! 7. Ra3 Kf2 8. Ra4 g3 9. Kh3 Rh1 and black wins.
So, I think black can win with Kg6. He should also win with an immediate f5:
The key insight is to get a passed f-pawn in this position rather than a passed g-pawn. Black must be able to drive the white king from the g2 square. Nice puzzle- I really learned something important about this type of endgame today.
The key is that White’s King can’t leave the 2nd rank due to the threat of check by the rook followed by promotion, and White’s rook can’t leave the a file without giving check, for the same reason.
1…f5 looks strong, leading to a passed f-pawn instead of the passed g-pawn, thus allowing the Black King to make progress. For example, 2.fxg5 Kxg5, followed by the King’s approach to f4 and e3 and either advance of the f-pawn or support of the a-pawn. Phil
1…f5! ensures that Black keeps a passed f-pawn. (On 2.Rxf5, Rb1 (among others) wins.) Black then pushes the pawn to f3, forcing Kf2, whereupon …Rh1!, meeting Rxa2 with …Rh2+ and …Rxa2, wins.
f5 wins, if Rf5 then Rg1+ and black queens. Black needs an f pawn to play f3+ as this will force the white king from the safe squares of g2 and h2 to take the pawn this allows Rf1+ and a1+q. if Kf2 Rh1 wins the rook after Ra2 Rh2+ and Ra2 or black queens the a pawn. A very valuable rook and pawn endgame from Susan.
Well, there are several options for black-king moveslike Kh4, Kg4, Kh6, Kg6, and the pawn move f5. Of course, we can eliminate all the possible rook moves due to white playing Ra2. I guess my first real thought in this position is, “Can I get the king over to b3 to support the pawn?” However, my experience tells me that long range rook checks from white will make this a hopeless task. At this point, I don’t have a plan to just jumps out at me. The white rook can’t leave the a-file without delivering check, otherwise black moves his rook laterally and forces white to sacrifice his rook for the pawn. The white king cannot advance to the third rank without allowing a rook check from black that again forces the exchange of the white rook for the a-pawn. I am more or less forced to consider each possible line separately and see if I can learn anything from the resulting positions:
Option A with 1. ….Kg4:
This is the move that looks most “natural” to me, but I already suspect it sucks for exactly that reason:
1. …..Kg4
2. fg5 fg5 (what else?)
3. Ra4 Kf5 (Kh5 below)
4. Ra5 Ke4 (what else?)
5. Ra4 Kd3
6. Ra3 Kc4
7. Ra8!
Here, 7.Ra4 loses to Kb3. Continuing:
7. …..g4 (what else to try?)
8. Rc8 Kb3
9. Rb8 and, white can check with impunity from the 8th rank, and if the black king tries walking him down, the white rook returns to a3. At move 3 above, I don’t think black can do any better with
3. …..Kh5
4. Ra5 Kh4
5. Ra4 g4
6. Ra5 g3 (Rd1 7.Ra2=)
7. Ra3 Kh5(Kg4 or Kg5 8.Rg3+)
8. Ra5 and we have almost the same position as before- the white king cannot be used to support the a-pawn without endless long distance checks from the white rook.
Option B with 1. ….Kh4:
I suspect this move is no better than Kg4.
1. …..Kh4
2. fg5 fg5
3. Ra4 and there is no need to go further with this as it is same type of dry draw as we have already seen.
Option C with 1. ….Kg6:
1. …..Kg6
2. fg5 f5 (fg5 like lines above)
Now, this does look different than the lines above. At some point black can play f3 with check. This may not seem important, but it does offer black the opportunity to play Rh1 should the white king move to f2- the point being that Ra2 is answered by Rh2+ X-raying white’s rook. Continuing:
3. Ra6 Kg5
4. Ra4 f4
5. Ra5 Kg4
6. Ra4 Kf5
7. Ra5 Ke4
And, now, black is threatening f3. White can continue to check from the a-file for two more moves:
8. Ra4 Ke3
9. Ra3 Ke2
And white is in zugzwang. There are two basic options for white- Ra6-8 or Kh2:
10.Ra8 f3+
11.Kh2 f2
12.Re8 Kd3
And black will walk the white rook down traveling up the e and d-files until he forces the rook to move away for a move just long enough to queen the f-pawn. At move 11 in this line, white still loses with
11.Kg3 Rg1
12.Kh2 a1(Q) At move 10, white still loses with
10.Kh2 f3
11.Ra8 f2 and we transpose into the lines above in which black walks the white rook down on the 8th rank. In this line, the only other option seems to arise at move 2. From the top:
1. …..Kg6
2. f5 Kh5
3. Ra4 g4 (clearing g5)
4. Ra3 Kg5
5. Ra5 Kf4
And white is in zugzwang again- either lose the f5 pawn or move the king to h2 or f2. Losing f5 loses the game as black will win easily by pushing the connected pawns:
6. Kf2 Rh1
7. Ra4 Kf5 and black wins. Or
6. Kh2 Kf3!
7. Ra3 Kf2
8. Ra4 g3
9. Kh3 Rh1 and black wins.
So, I think black can win with Kg6. He should also win with an immediate f5:
1. …..f5
2. Rf5 Rg1
3. Kg1 a1(Q)
4. Kg2 Qb2
5. Kf3 Qb3
6. Ke4 Qe6
7. Re5 Qc4
And black wins the f-pawn and the game.
The key insight is to get a passed f-pawn in this position rather than a passed g-pawn. Black must be able to drive the white king from the g2 square. Nice puzzle- I really learned something important about this type of endgame today.
The key is that White’s King can’t leave the 2nd rank due to the threat of check by the rook followed by promotion, and White’s rook can’t leave the a file without giving check, for the same reason.
1 … f5
2 fg Kg5
3 Ra4 f4
4 Kf2 f3
5 Ra3 Kf4
6 Ra4 Ke5
7 Ra3 Kf4
8 Ra4 Kd3 etc.
1…f5 looks strong, leading to a passed f-pawn instead of the passed g-pawn, thus allowing the Black King to make progress. For example, 2.fxg5 Kxg5, followed by the King’s approach to f4 and e3 and either advance of the f-pawn or support of the a-pawn. Phil
To win, Black must not be left with only the a pawn and the g pawn. Therefore, 1. … Kg6, and, if 2. fg5:, then 2…. f5! followed by Kg5:
1…f5! ensures that Black keeps a passed f-pawn. (On 2.Rxf5, Rb1 (among others) wins.) Black then pushes the pawn to f3, forcing Kf2, whereupon …Rh1!, meeting Rxa2 with …Rh2+ and …Rxa2, wins.