Mate or Draw?

Here is an interesting position.

It is white to move.  If white plays a move (can only move the knight), black checkmates with the bishop.  This is a blitz game and white believes since black does not have mating material on the board, black can not win.  So, white lets the clock time run out and claims a draw!  Is this correct?

Black wins with mate on the move. 

No he mean since black seemingly does not have sufficient material to checkmate,but infact it is checkmate on next move,is it draw or black win if white rans out of time

The answer should be black wins,similar to the 2 knight vs bare king rule,since there is other piece present,there is still chance for checkmate.

Dunno if chess.com use engine evaluation bar to detect drawn position tho

On chess.com you can try that because it lacks an algorithm to detect dead positions. Instead it rewards "insufficient mating material" which is not a FIDE authorized criterion.

If white runs out of time, then black wins. The USCF rule for a draw would be that black "has only king and bishop... and does not have a forced win." Since he DOES have a forced win, he wins! To just use the phrase "insufficient mating material" is incomplete.

Of course that would be true - if the verdict was rendered by a human. But it is unlikely that chess.com's robotic arbiter would take that into account.

The problem is that there is no definition of "forced win". An irrefutable win in 547 moves could also be considered a forced win but who would do the analysis?

Either person to move black has Be4# no way to stop it

The one key bit of information missing is where the game was being played.  Chess.com does not take the position into account, only the material available - making it a draw upon White flagging.  FIDE and USChess rules take the position into account - making it a Black win upon White flagging.  Some weak elementary school clubs run by a sponsor that is weak at chess would simply count up the value of pieces when the time ran out - making it a White win when the time allotted for the game is up (generally such clubs do not have chess clocks and thus it would be the end of the playing period).

Chess.com should use engine evaluation bar when ending a game with insufficient material vs time out

(or do they don’t trust their own engine)

Interestingly this debate is very much like debates about adjournments in the previous century. When games couldn't be resumed a human arbiter would judge adjourned positions. And a player at 1300 rating level would come up with a game between Lasker and Capablanca with a similar ending to his and request the arbiter to grant the same victory scored by Capa. Now we want to do the same with the engine in the roles of the GMs and arbiter. Should it consider the ending between R+B vs 2N a forced win? Is that realistic given the strength of the players?

i feel a greater sense of satisfaction when the victory resides from checkmate instead of resignation. the enemy who surrenders is the coward who doesn't dare face defeat in the eyes of sacrifice. only a true warrior can plunder their opponents with bravery. a hero without sacrifice is a villain without sacrifice. resignation does not speed the process but instead eliminates the honour. in other words: fight till the end, there is no shame in defeat. as long as you went down with glory.

hi I'm wondering if someone could help me. I'm a beginner and I've just played a game where it said that I lost but I can't see how as I could still move my king, this has happened twice today so I think I need some clarification on checkmate not sure how to share the screen shot though.

erm you accidentally clicked resign?

it says your opponent won by resignation

Sufficient mating material.

Insufficient mating material. 

Insufficient mating material (white to move)Draw by stalemate.

Sufficient mating material (black to move)

And just to point out another difference, if the White pawn was on a6 instead of a7 then FIDE would rule Black having sufficient mating material (helpmate is possible) while US Chess would rule Black having insufficient mating material (checkmate is not forced).

I think the black wins.

It shouldn't be insufficient material. I think they have an engine background, if black is winning he should win after white timeouts, but I am not sure.