throwing away wins against Computer4-IMPOSSIBLE

I sometimes like to observe players taking on the computer in Live Chess, usually Computer4-IMPOSSIBLE. I am fascinated by the way the weaker players (rated around 1200-1450 or so) are thoroughly trounced. I am also intrigued by the way stronger players compete with and occasionally beat the machine.

However, I observe a handful of players do something very strange when playing against Computer4-IMPOSSIBLE. I have witnessed at least a half-dozen different players recently deliberately throw away their victories against the machine.

A couple weeks ago, I saw a low-rated player (around 1400s) use much of his time; he toiled and persevered, traded down to an endgame, outplayed the computer in the endgame and promoted a Pawn to a Queen. The win was very basic from here, but he proceeded to fumble, moving his Queen to strange squares, clearly not pursuing the win, and eventually placing the Queen where the computer's bare King could capture it. Draw: insufficient material!

Also some time ago, I saw a rather strong player outplay the computer easily. The player moved with great swiftness and confidence, met all the computer's threats while administering his own, and achieved a sizable material advantage in the late middlegame. He easily converted the advantage and promoted two Pawns to Queens. He clearly knew how to win. But once he obtained the Queens, his style changed abruptly. He began to move much more slowly, and he moved his Queens to surround the opposing King but without giving check. He ignored several mates-in-1 as he continued in this manner. He eventually reached a position where he cornered the enemy King and threatened three different mates-in-1, but instead, after a lengthy pause, he moved a Queen to give stalemate!

Finally, tonight I saw a 2200-rated player obtain a Rook-for-Knight advantage in the endgame. He sacrificed his Rook to achieve a winning King-and-Pawn endgame. He soon had a King and Queen against a King and Pawn. The enemy Pawn was on the 5th rank and could have been stopped easily. Instead, he offered a draw, and the computer took it!

My question is, why do multiple players keep throwing away these extremely easy victories against such a difficult opponent? They evidently work very hard, but they refuse to reap the rewards of their arduous labors.

Well, the answer is so obvious :-)

The winning against high rated computer is very often an indication of cheating, especially when it applies to a weaker player. Players understand it and simply do not want that it shows up on their play history.

That seems awfully paranoid to me! Merely beating the computer on that setting does not indicate cheating. If Chess.com investigated all wins against Computer4-IMPOSSIBLE, then surely their standard methods of analysis would reveal that their moves were not similar enough to an engine's (assuming they are not cheating). I think this explanation is highly unlikely; I doubt most players who are skilled--or lucky--enough to defeat the computer would think of this ramification as they apply the coup de grâce after an impassioned struggle.

As I thought about this some more, I realized that there was another reason that explanation doesn't work. In the first two examples I gave in the OP (and especially the second example), the players fumbled around for many moves and eventually caused the game to be drawn. If the players of those games achieved a completely winning endgame and then realized, at any point during the game, that they would need to throw away the win in order to allay suspicions of cheating, then they would immediately hang their Queen, or immediately give stalemate, not fumble around indecisively as if they'd forgotten basic winning technique.

I had exactly such a situation a while back. I retorted by creating this thread of things I'd like to do to Comp-4: http://www.chess.com/forum/view/livechess/things-i-would-like-to-do-to-computer4-impossible

No intention of detracting from this thread (OK, maybe a little ). In fact, here's my explanation for the game I mentioned: I dropped my queen because I simply didn't see it would be captured on that square. I was concentrating, but not on the squares my opponent could attack (basically, an absolute beginner's mistake).

Very funny ideas in that thread! I loved the way you won the Queen with that Kingside attack, too! Thanks for sharing that game. Yes, the 49th move was painful to watch, but until that point your play was impressive.

Actually, though, the game you shared doesn't fit the profile of those I've described above. You blundered your Queen quite a bit earlier in the endgame than these other players. Your 49th move was clearly a blunder, not a move that deliberately threw the game. In the strange games that I've seen, the players waited until the very end before blowing it. It was either 1) K+Q v. K, 2) K+2Q v. K, or 3) K+Q v. K+P.

excuse me its mean computer4- IMPOSSIBLE is not a original rating its mean that is world class like grand master ???

I'm confused. I play against the computer at level 9. I once had the computer fishish a game my opponent resigned. It suggested a move I thought to be inferior to the move I planed to play. My coach agreed. I then saw that level 9 rating was 2000 so I switched it to 10 which is 2600. Are we playing the same computer?

@kellypk417: Computer4-IMPOSSIBLE is the toughest computer opponent in Live Chess.

You may be referring to the computer found by clicking Play > Vs. Computer.

@mhikefrancesmarban: Computer4-IMPOSSIBLE is not quite as difficult as grandmaster strength. 

        I have noticed players resigning in either favourable positions against Computer 4 Impossible, or in positions where they were in no immediate danger of losing or even conceding an advantage against the machine. Clearly in these instances, something was going on. I don't doubt that the OP is corect in his observations. Furthermore, I am not referring to "Play v Computer".