King + 2 Pawns vs. King + 1 Pawn - How to win?

I know in most 2 connected pawn vs. 1 pawn endgames you can just trade pawns and win the game like you would a 1 pawn endgame, but I am not sure how to win this endgame position:

It's a bit more complicated than trading the pawns.  White needs to outmaneuver the opposing King as well.

This particular ending is very tricky.   My suggestion is to consult a tablebase and figure out why some moves work and others don't.  Shredder Online has an endgame tablebase.

The first point. Black is losing if he ever advances the a-pawn. White will advance his own a-pawn so the pawns are locked, manuveur his king to the same rank as the black pawn, then use zugzwang to force the Black king away from the defense of the pawn.

Note that this doesn't work with the pawn on a7. Put the White pawns on a6 and b2, White king on c7, and black king on a8. With Nlack to move this is a stalemate. With the pawn anywhere except for a7, the Black king would have to back up and allow White's king to move next to the Black a-pawn.

The second point. White wants to get his king to a6, and then advance his a-pawn to a5. The Black king must be on a8 or b8 to defend. This is the ideal position for White. 

The third point.  The winning procedure from the ideal position is to advance the b-pawn so it reaches b7 without giving check. That means the pawn should always move to a square that is the opposite color from the square occupied by the black king.

The fourth point. White MUST NOT MOVE HIS B2 PAWN until he has achieved the ideal position. The option to move one square or two is critical. In the ideal position with Black's king on b8, White plays b3. In the ideal postion with Black's king on a8, White plays b4.

The fifth point. When Whites b-pawn reaches b7, with or without a pawn trade on b6, Black's king will be on b8. He will be forced to move the king to c7. Then White plays Ka7 and queens the pawn.

Thanks splane. State was last week and someone was telling me that, but i wanted to get the points straight :D

Chess is sometimes so easy. Here, a guide!  

Here are some lines:

Fezzik, the mistake in Zchess' line is the terrible fourth move, 4. b4?, instantly turning a win into a draw. The winning idea is 4. Kd5 Kb7 5. Kc5 Ka6  6. Kc6 Ka7  7. Kb5. This type of maneuver, with locked pawns and one side having an advanced king, is called outflanking. I described this idea as my first point in post #4 in this thread.

 Sorry, I disagree. I think White can get his king to a6 and win no matter what Black tries. Once the king gets to a6 the winning technique is described in post #4 in this thread. Here are some sample lines.

3. ... Ka5   4. Ka3 Ka6  5. Kb4 Kb6  6. a5+ Ka6  7. Ka4 Kb7  8. Kb5 White's king reaches a6 and wins.

3. ... Kc6 4. Kb4 Kb6  5. a5+ Ka6 6. Ka4 Kb7 Kb5 and wins.

3. ... Kc6 4. Kb4 Kb6  5. a5+ Kc6 6. Kc4  Kb7  7. Kb5 and wins.

3. ... Kc6 4. Kb4 Kb6  5. a5+ Kc6 6. Kc4 Kc7  7. Kc5 Kb7  8. Kb5 and wins.

Sorry, but you're wrong according to the endgame tablebases used by shredderchess.com. 3...Ka5 and 3...Kc6 will draw, just as Fezzik said.

In your sample lines, 4. Ka3 is an illegal move as the white king is placed on c4 and in the other line (3. ... Kc6 4. Kb4 Kb6  5. a5+ Kc6 6. Kc4 Kc7  7. Kc5) black will draw with 7...Kb8 or 7...Kc8.

But one of the variations win (4.b3!)

But the 3rd move I agree it is a mistake,I think Fezzik could be right!

Thanks guys! I learned something today!

Oops,its just a quick analzye.

Thanks

                                                                                                       From,

                                                                                                       zschess. 

What about if the White King is on the a-file instead of the c-file? Can black force a draw?

No, the White King is even better placed on the a-file.

Thanks, Sred. I just lost a game as black in this position, so at least it's good to know that I couldn't have forced a draw anyway, lol.

Well i played this position against komodo 8 like 10 times white and 10 times black all resulted in white' winning no matter who defended me or computer. Idea is get close keeping opposition and outflank by going d-file when necessary. you can then play a3 to lose tempo if necessary since black cant capture b2 without losing his a pawn first then you can play a4 (since black king is b2 it wins easy) You either get touch black pawn from behind or from front. (If he doesnt move from front, if black ever moves a-pawn then behind, and i saw a varitian white managed to get a pawn from side and get is without losing single pawn) Although didnt checked it with tablebase check all the reasonable lines and white won all of them.

Try Qh8+