Can someone explain this computer play?

Computers seem to play very interstingly, every bad move seems to have a decent reason, but if the computer cannot search far enough he simply does not see it, however that does not explain his wasteful rook give away, the blunders during the promotion period are explainable, he prefers to lose pieces to delay promotion.

bump?

Unlike humans, an engine isn't capable of mediocre play.  So to dumb itself down it makes periodic blunders.  Another reason why playing humans is better.

I see, I usually noticed it made dumb moves depending on how many i alloted it, if it is only allowed to see 4 moves forward and it seems good it will do it despite my 5th responce possibly being cripling.