How to proceed in this endgame position?

Question

[FEN "3k4/ppp3pp/1b6/8/PP6/4BpP1/5P1P/6K1 b - - 1 24"]

This position is evaluated -4 but i cant find any plans for Black and lost. What should have been my strategy from this position ?

This is the full game :

[Event "Rated Rapid game"]
[Site "https://lichess.org/xxLijzuK"]
[Date "2020.04.08"]
[Round "-"]
[White "CorsaireBouritos"]
[Black "AKP2002"]
[Result "1-0"]
[UTCDate "2020.04.08"]
[UTCTime "06:59:51"]
[WhiteElo "1214"]
[BlackElo "1228"]
[WhiteRatingDiff "+6"]
[BlackRatingDiff "-6"]
[Variant "Standard"]
[TimeControl "600+0"]
[ECO "B02"]
[Opening "Alekhine Defense: Scandinavian Variation"]
[Termination "Normal"]
[Annotator "lichess.org"]
[FEN ""]

1. e4 Nf6 2. Nc3?! { (0.63 → 0.00) Inaccuracy. e5 was best. } (2. e5 Nd5 3. c4 Nb6 4. d4 d6 5. f4 g6 6. Nc3 Bg7) 2... d5 { B02 Alekhine Defense: Scandinavian Variation } 3. Nxd5 Nxd5 4. exd5 Qxd5 5. c3?! { (0.08 → -0.48) Inaccuracy. d4 was best. } (5. d4 Nc6 6. Be3 e5 7. Nf3 exd4 8. Nxd4 Nxd4 9. Qxd4 Qxd4) 5... Nc6 6. d4?! { (0.00 → -0.75) Inaccuracy. Qf3 was best. } (6. Qf3 Be6 7. d4 O-O-O 8. Be2 h5 9. Qxd5 Bxd5 10. Nf3 h4) 6... e5 7. Nf3 e4?? { (-0.94 → 0.70) Blunder. exd4 was best. } (7... exd4 8. Nxd4 Nxd4 9. Be3 Bc5 10. Bxd4 Bxd4 11. Qxd4 Qxd4 12. cxd4) 8. Ng5? { (0.70 → -0.42) Mistake. Nd2 was best. } (8. Nd2 Be7 9. Nc4 O-O 10. Bf4 Qd8 11. d5 Nb8 12. Be2 Nd7) 8... Be6?? { (-0.42 → 1.92) Blunder. h6 was best. } (8... h6 9. Nh3) 9. Nxe6 fxe6 10. g3?? { (1.71 → 0.13) Blunder. Qb3 was best. } (10. Qb3 Qxb3) 10... e5?! { (0.13 → 0.97) Inaccuracy. e3 was best. } (10... e3 11. f3) 11. Bg2 exd4 12. cxd4?? { (1.01 → -1.30) Blunder. Qg4 was best. } (12. Qg4) 12... Nxd4?? { (-1.30 → 0.36) Blunder. Bb4+ was best. } (12... Bb4+ 13. Bd2) 13. O-O O-O-O 14. Re1?? { (0.28 → -1.35) Blunder. Qg4+ was best. } (14. Qg4+ Kb8) 14... Nf3+ 15. Bxf3 Qxd1?? { (-1.29 → 5.46) Blunder. exf3 was best. } (15... exf3 16. Qa4 Bc5 17. Be3 Bxe3 18. Rxe3 Kb8 19. Qg4 Qxa2 20. Ra3 Qd5 21. Qxf3 a6 22. Qxd5) 16. Rxd1?? { (5.46 → -0.76) Blunder. Bxd1 was best. } (16. Bxd1) 16... exf3 17. Rxd8+ Kxd8 18. Bf4 Bb4?! { (-1.27 → -0.58) Inaccuracy. Bc5 was best. } (18... Bc5) 19. Rd1+ Kc8 20. a3 Ba5 21. b4 Bb6 22. a4? { (-0.94 → -2.07) Mistake. Rd3 was best. } (22. Rd3 Rf8 23. h4 h6 24. Kf1 a5 25. h5 Rf5 26. Rxf3 Rxh5 27. Bd2 Rd5 28. Ke2 Re5+) 22... Rd8 23. Rxd8+?! { (-1.57 → -2.63) Inaccuracy. Rc1 was best. } (23. Rc1) 23... Kxd8 24. Be3?! { (-2.54 → -3.85) Inaccuracy. h4 was best. } (24. h4 Kd7 25. Be5 a5 26. bxa5 Bxa5 27. Bxg7 Ke6 28. h5 c5 29. Kh2 c4 30. Kh3 Kd5) 24... Bxe3 25. fxe3 g5 26. g4?! { (-2.39 → -3.53) Inaccuracy. h3 was best. } (26. h3 h5) 26... b6?? { (-3.53 → 0.00) Blunder. Kd7 was best. } (26... Kd7 27. Kf2 c5 28. bxc5 Kc6 29. a5 Kxc5 30. Kxf3 b6 31. a6 Kc4 32. Ke4 b5 33. Kf3) 27. b5?? { (0.00 → -2.46) Blunder. Kf2 was best. } (27. Kf2 Ke7 28. Kxf3 c6 29. Ke4 Kf6 30. Kd3 Ke5 31. e4 h6 32. h3 Ke6 33. Kc3 Ke5) 27... Kd7? { (-2.46 → -1.22) Mistake. Ke7 was best. } (27... Ke7 28. Kf2 c5 29. Kxf3 Kd6 30. Ke2 Kd5 31. Kd3 Ke5 32. Kd2 Ke4 33. Ke2 c4 34. Kd2) 28. Kf2 Kd6 29. Kxf3 Kc5?? { (-3.08 → 0.00) Blunder. c6 was best. } (29... c6) 30. e4?? { (0.00 → -2.66) Blunder. Ke4 was best. } (30. Ke4 c6 31. bxc6 Kxc6 32. Ke5 a6 33. e4 b5 34. axb5+ axb5 35. Kf6 Kd7 36. Kf7 Kd6) 30... Kb4?? { (-2.66 → 12.85) Blunder. Kd4 was best. } (30... Kd4 31. h3) 31. e5 Kc5 32. Ke4 h5 33. gxh5 g4 34. e6 Kd6 35. Kf5 Ke7?! { (25.19 → Mate in 9) Checkmate is now unavoidable. Kc5 was best. } (35... Kc5 36. e7) 36. h6 Kf8 37. Kf6 Kg8 38. e7 Kh7 39. Kg5 { Black resigns. } 1-0

Answer 1

This is a very common kind of endgame, where you have a pawn majority on one side and fight against a single pawn in the center. Winning this is not difficult, but let's first look at your game...

You

• fixed the position of the queenside pawns by playing b6 (to which white cleverly replied b5
• ran with your king towards the queenside

Basically you should do the opposite:

• keep your king in the center close to the white e-pawn (say around e5, d5, e4 or c4), which white cannot advance
• try to create a passed pawn on the queenside: for this you want to start with a6 or c6, not b6.

The idea then is to have that a-b-c passed pawn run, forcing the white king away from the protection of the kingside pawns

One possible line with comments....

[FEN "3k4/ppp3pp/1b6/8/PP6/4BpP1/5P1P/6K1 b - - 1 1"]

1... Bxe3 { Perhaps not the computer's first choice but a decent practical human decision to turn it into a clearly won pawn endgame. Could perhpas have delayed this exchange to gain an extra tempo (for centralizing the king) since white does not have any good moves. } (1... a5 { Prevents white from playing a5. Objectively the strongest move in the position. The main idea is to keep the white king out of play for as long as possible. } 2. bxa5 (2. b5 Kd7 3. Kf1 Kd6 4. Ke1 (4. Bd2 Kd5 { and white does not get anywhere as the king is bound to the protection of the f2 pawn, black can just collect the a and b pawns or promote the c pawn as he wishes. }) 4... Bxe3 { now is the time to exchange because black will keep the f3 pawn } 5. fxe3 Kd5 6. Kf2 Ke4 { followed by c5-c4-c3-c2-c1Q 0-1 }) 2... Bxa5 { The white king's path to freedom via f1 e1 is now blocked. Black is basically playing king+bishop+pawn vs a single bishop. } 3. h4 { trying to activate the king via h2 } 3... Kd7 { centralizing the king } 4. Kh2 Kc6 5. g4 Kd5 6. Kg3 Ke4 7. Bc5 (7. g5 g6 { the white king has no way to escape and black just pushes the c pawn to c1 }) 7... b6 8. Bf8 g6 { and black will just push the c pawn to c1. }) 2. fxe3 g5 { threatening to create a protected passed pawn on f3. } 3. g4 Kd7 4. Kf2 Ke6 5. Kxf3 Kd5 { First goal achieved: King is centralized. Note that white can never play e4 since after Kd4 white will eventually run out of moves and will have to move the king from the protection of the e pawn. } 6. b5 c6 { or a6 or c5 all will create a passed pawn for black } 7. bxc6 { basically forced because otherwise black would end up with one vs zero pawns on the queenside, which would make his task even easier } 7... bxc6 { Second goal achieved: black has a passed pawn } 8. a5 c5 9. Ke2 Kc4! { Aiminig for the a5 pawn, while keeping an eye on the e3 pawn (which would still be lost after e4 Kd4). Also the black king is threatening to get to d3 after which white would also be lost. } 10. Kd2 { basically forced, because black was also threatening Kc3 after which he'd get to d3 when white runs out of pawn moves } 10... a6 11. Kc2 Kb4 12. Kd3 Kxa5 { Again this is the more human decision. Black could also go for pawn promotion with Kb3 (followed by c4...). It is important to realize that black can catch the e pawn (rule of the square). Also it helps that the lone white king is lost against the a and c pawn (even without the black king's support). } 13. Kc4 Kb6 14. e4 a5 15. Kd5 (15. e5 a4 16. e6 Kc6 17. e7 Kd7 { and the white king is lost against the a and c pawns }) 15... a4 { I am faster than you. Needs to count. } 16. e5 a3 17. e6 a2 18. e7 a1=Q 19. e8=Q Qd4+ 20. Ke6 Qe3+ { and black trades queens and will get a new queen soon on c1. } *

Answer 2

I think you should avoid taking on e3, even though it is objectively winning, this gives your opponent a passed pawn on e-file and exposes your f3-pawn (which is a big headache for white), this complicates the game.

If you don't take on e3 yourself, you opponent can force you with a5, is there a way to stop that? Yes, there is: play 1...a5 yourself, if 2.bxa5 Bxa5, just march you king to e4 and push your pawns on the queen side. For anything else white pawns on the queen side will be too weak, you can just march your king over and take them.