Computer Analysis

Depends whether you're judging the play from a human perspective or "objectively". Think the OP was looking for "objective" strength

until chess is solved, there is no objective strength. so, no, it can't be measured by computer.

Then I believe enjaytee is correct. There is only engine matchup strength, or practical strength. Objective strength is as of yet unknown.

and even where it is solved, if I make a mistake in a 6 piece endgame, but still win, how can anyone call it a mistake? I don't have the tablebase, neither does my opponent. If I use my knowledge of the fact that my opponent doesn't have the tablebase, I'm playing better than a computer, even if the computer thinks I made a mistake. the computer is wrong.

Yeah I remember watching a Nakamura game on chessbomb. He made a move against Yifan which was clearly simplifying to an easily winning endgame but everyone was criticising him because Houdini turned red. That has nothing to do with strength, he knew there were 'better' moves, but his was the easiest.

I think J. T Kirk vs Mr Spock, 1967, 3d chess variant, 1-0, is the canonical example.

the full scoresheet will be available in 250 years.

it's horrible posting the last thing. makes me feel like at a party joining a conversation and everone walks away in different directions mumbling. everyone here knows that feeling right, since you all play chess? somebody at least come in and say 'we can't post in this thread any more because some idiot started talking about Spock'.

Batgirl, the simple answer is yes.

Rather than matching the player's moves to some set of top-n computer moves, there's a more general and likely more robust metric: Use the computer to estimate the value of the player's actual move; this could be the difference between the evaluation of the position before the player moves and the evaluation of the position immediately after the player moves. With best play, the evaluation should not drop (from that player's perspective) from right before to right after that player's move (because the evaluation assumes the player will play the best move). Therefore, the smaller the drop as a result of the move, the better the move.

I'm surprised nobody's mentioned this yet: http://en.chessbase.com/post/the-quality-of-play-at-the-candidates-090413 , http://en.chessbase.com/post/computer-analysis-of-world-champions (I think there's a couple others out there).

It's true that Super GM's match with 3200 Elo rated engines to a greater degree than GM's, who in turn match to a greater degree than IM's, FM's & so on.

Engine match rate correlation does not really test for comparative strength though, it tests for engine-like play.  Even Carlsen, Kasparov, Fischer & Kramnik only play engine-like chess to a certain degree.  Humans play to a series of human plans.  Engines constantly go off on tangents of tiny fractions of a pawn at depths of 20 ply where they see a minuscule advantage that the very best human player wouldn't see.

When Super GM's have a perceived advantage in a position they will try to simplify & play safe & solid moves.  They won't go for an incredibly sharp, risky tactical line which would further win the already won game. 

Short answer : yes.

But technicalities are hard to overcome. For example, do you trim out trivially winning positions ?

Paul Morphy's Chess Strength.