playing against computer--question

I was just playing a game against the computer, and I was about to achieve checkmate.  "he" only had a king and one pawn, and I had two rooks, a knight, a bishop, and a pawn that was about to be queened.  And then, on move 51, it said, "game over--draw".   How in the world can that be a draw??

It's likely that you got stalemate.

I tried to find a way to copy the moves to post here, but the page wouldn't let me do it.  How could it be stalemate?  the king was not in check, but could move without getting into check.  

[Site "Chess.com"]

[Date "2012.02.27"]

[White "Player"]

[Black "Computer - Hard"]

[Result "½-½"]

 here's the game!  :-)  

1. e4 Nc6 2. d3 e5 3. Nf3 Qf6 4. Nc3 Bb4 5. a3 Bxc3+ 6. bxc3 Nge7 7. d4 d6 8. Bb5 O-O 9. Bg5 Qe6 10. O-O exd4 11. cxd4 Qxe4 12. Re1 Qd5 13. c4 Qxg5 14. Nxg5 Bf5 15. d5 Nxd5 16. cxd5 Ne5 17. Nf3 f6 18. Nd4 Bg4 19. h3 Bxd1 20. Rexd1 a6 21. Ba4 f5 22. Ne6 Rf7 23. f4 b5 24. Bb3 c5 25. fxe5 c4 26. Bc2 dxe5 27. Re1 e4 28. Ng5 Rd8 29. Nxf7 Rxd5 30. Ng5 h6 31. Ne6 Re5 32. Nd4 a5 33. Rab1 b4 34. axb4 Kf8 35. Nc6 axb4 36. Nxb4 Ke7 37. Nc6+ Kd6 38. Rb6 Re8 39. g4 fxg4 40. hxg4 e3 41. Bg6 Re6 42. Nd4+ Kd5 43. Nxe6 Ke5 44. Nxg7 Kd4 45. Ne6+ Ke5 46. Rxe3+ Kf6 47. Bc2 h5 48. gxh5 Kf7 49. Rb7+ Kf6 50. h6 c3 51. h7 

It's stalemate. It is black's turn. He has no available move and his king is not in checked.

Take a look at the final diagram.

you're right!  I was going from memory when I said that, because I couldn't find a way to bring up the diagram the way you did.  Did I therefore make a wrong move one or two moves prior to that point, to allow the stalemate to occur?  

thanks for taking the time to help me see this-- I appreciate it.

I would say you would have won but let your guard down and instead of 51. h7 maybe go rb6 so you can drive king.

The last move 51.h7 was the mistake. 51. Rb5 is better, followed by h7 and h8. You need to give Black a move.

thanks-- oh well, live and learn.  and here I thought I had been doing quite well to be beating the computer so handily :-)  this might be an elementary question, (just thinking aloud here), but why isn't stalemate = checkmate?  if black can't move without putting himself into check, then couldn't one interpret that as having won the game?  I know those aren't the rules, but I guess what I'm wondering is, why not?  

In other words, what is the difference between putting the king in check, and him being unable to move without putting himself into check (thus, checkmate), and making a move that doesn't put the king into check, but the king is the only piece on the board that can move, and he can't move without putting himself into check.   (I know there is an actual difference, (in one case the king is in check, and in the other not), but what is the significance of that difference?)

in the ancient chess, stalemate used to be a win for the other player. Now it is a draw, because it's been considered that in stalemate, the opposing king is not directly under attack from any piece, which is less significant. whereas in checkmate the king is being hit and cannot do anything about it. stalemate also gives the player in a worse position an opportunity to still acheive a draw, and that introduces another range of tactics into the game.

I always thought the same thing, but you can't put yourself in mate during games (computer won't let you and you can't lose that way) so I guess the same principal applies. It's just the way the rules are. It does give one thought when you are chasing king. Also, on the other hand, when you are getting beat and mate is likely then look for a way to force stalemate, I did it once or twice. It's something many players don't look for probably, like you found out.

HAHAHA

You blew it by pushing that pawn on your last move.  What you should have done was seen that black had no available place to move, and given some breathing room.  It's easy to get caught up in the chase and twist your ankle.  I've done it more times than I care to remember.

I put together a puzzle to illustrate one reasonably quick way to win from there.  I apologize in advance to everybody who will comment that such and such wasn't the best move for whatever side.

I didn't like the simulated 3D pieces at first, but I played with them for awhile, and I got used to them.  The effect isn't bad.  It isn't great, but it isn't bad.

I have no idea what the protocol is for using what settings when posting puzzles and such.  The editor provides a lot of choices, and I see other people using some of them from time to time.

I'm kind of trying to get a feel for all of this by seeing how people react, and I thought I'd start by using the same settings in my diagrams that I use on my boards here. It looks nice to me, but maybe it's shocking and obnoxious to everyone else.

If so, tell me so, and that's how I'll learn to avoid being obnoxious.

arborvitian-- thanks for the puzzle!  a nice clean solution.

yeah, I see what you mean about twisting your ankle in the chase :-)

Jared and King of pawns-- thanks for those thoughts about stalemate.  I didn't know about the history.  interesting to think about why the rules are what they are :-)