Evenly distributed

Logic Level 1

It's White turn, what is the minimum number of moves White should make to guarantee he/she wins the game?

Assume that both players played optimally and that White moves up and Black moves down (pawn).

Designed by Fauzi Al Zahri.

6 2 5 4 3

4 solutions

Terza Reyhan
Jun 2, 2015

Claim: White could win in 2 moves with Qd6-c7.

We analyze the game according to the possible responses of Black to this move. Notice that all of the black pawns are blocked, and so the black king can only move to d5, d4 or d3.

A. 1. Qd6-c7 | Ke4-d5, 2. Qd6-c4 #

B. 1. Qd6-c7 | Ke4-d4, 2. Qd6-c4 #

C. 1. Qd6-c7 | Ke4-d3, 2. Qd6-c4 #

Moderator note:

Wonderful. Can you explain the motivation for moving back your queen?

I like how "retreating" the queens is always the initial step!

Still got one more!

D. 1. Qd6-c7 | Ke4 f5. 2 Qc7 - e5 #

Pi Han Goh - 6 years ago

I believe you meant 2-Qc7-c4 # not Qd6-c4 #

there's also one more variation to this

D.1. Qd6-c7 | Ke4-f5, 2. Qc7-e5 #

Ahmed Obaiedallah - 5 years, 11 months ago

can the black king not more to f5 in addition to d5, d4, d3 after Qc7?
but it would still be checkmate in 2 anyways

Tony Sun - 3 years, 5 months ago

what if it is blacks turn then what would you do

Asher LeGrand - 1 year, 2 months ago

think about it okay

Asher LeGrand - 1 year, 2 months ago

Doug Gwyn
Aug 11, 2016

The problem statement is wrong. If White can force a win after two moves, then from the starting configuration White doesn't need to make any moves to force a win. (Aug. 11, 2016) As of Nov. 23, 2016 nobody has addressed this. (Also note that White has such an overwhelming advantage in pieces and position that it would be hard for White to not win the game. E.g. 1. Qxh6, K any; 2. Q continues to capture all pawns; easily end up with K&Q vs. K which is a known won ending.) I think the problem statement should have asked for the number of moves in the shortest forced checkmate(s). Guarantees are irrelevant since we already see that this is a won position.

White has to move. Anyways King can go to f5

Zeke Aho - 4 years, 7 months ago

If Kf5 then Qe5.

János Rátkai - 4 years, 3 months ago

Jaimin Pandya
Jun 4, 2015

1 : Qe5 + Kd3 2: Be2 #

Why can't Kc3?

Pi Han Goh - 6 years ago

@Pi Han Goh Queen covers A1 H8 diagonal

Jaimin Pandya - 6 years ago

Oh I meant to say "Kc2".

Pi Han Goh - 6 years ago

@Pi Han Goh – Sorry My mistake , Luckily got right answer i.e. 2 without noticing Kc2

Jaimin Pandya - 6 years ago

Alternatively. Be5 first and then Qe5. The only move black got is to move the pawns (after Be5)

Chandra V - 4 years, 11 months ago

This is the way I figured :)

James Crowley - 4 years, 11 months ago

I meant Be2

Chandra V - 4 years, 11 months ago

Qe5 Check King has only one possible field
Qe3 Check King has only one field again
Qd2 Checkmate And he's dead ...

Or did I miss something

Jo Suedwind - 4 years, 4 months ago

Your solution is a mate in 3, while a forced mate in 2 is possible. 1.Qe5?! is not the best move, as the best continuation is indeed a mate in 3, see also Terza Reyhan's answer and the first reply to it (he missed one line).

Roland van Vliembergen - 2 years, 1 month ago

everything

Asher LeGrand - 1 year, 2 months ago

King can still move to C2

Amine Dak - 11 months, 3 weeks ago

Sathish Jayapal
Feb 19, 2021

I just guessed lol, it's 2.

Evenly distributed

Designed by Fauzi Al Zahri.

4 solutions

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