This is what I'm referring to when I say you are blindly supporting Petrosian. Botvinnik and Petrosian were both great players, and they were also both fallible. Botvinnik didn't just curl up and die once he became champion, he still played some great chess. And conversely, Petrosian did not become a god once he was champion. If he did he wouldn't have lost to Spassky in 1969. I suggest you take a look at Petrosian's performances in 1967: http://db.chessmetrics.com/CM2/Play...

<You think it's a big deal which year this occurred in. It isn't.>

It's a particularly big deal here because you made the same erroneous claim on numerous pages of this site. It was time to finally put a nail in the coffin.

<Try not to miss the forest for the trees.>

There was a time when 'great' used to mean something. Then, as usual, the word got over used. So, I remember Botvinnik's game against Larsen. We can put that down as a great game. Can you think of any others during this semi-retired phase of Botvinnik's that were all time greats? Because I'd have no problem pointing you to half a dozen grandmaster draws.

It was never "explained", you just stated it arbitrarily. That's your opinion. I don't agree with it, as I've told you before. I don't see why beating, say Kasparov at Linares is any less of a feat than beating him in a match. It's still Kasparov. Your objective is transparent: Fischer and Petrosian were far stronger match players than tournament players, so let's boost their ratings accordingly! The fact that world championship matches involve very strong players already introduces a weighting effect.

<Almost interesting.> This is a case in point. Why bother bringing facts to you? You'll just see what you want to see.

<When I was looking at the 1968 games, to find the game against Portisch cited above...>

Yep fine, and this correlates with the chessmetrics ratings: you'll see that Botvinnik's rating fell behind Petrosian's for good in November of 1968.

Returning to the <relevant point> (so pay attention), I'll show you why Botvinnik's rating overtook Petrosian's (briefly & barely) in early 1968. Consider their performances in 1967, and the first few months of 1968:

<Petrosian>
- Disappointing showing at Venice, being beaten by a clear point for 1st by Donner (ranked 47 in the world)

- Scores a highly disappointing 8.5/17 at Moscow, 1967.

- Performed at about par in his other 31 games.

<Botvinnik>
- Finished equal 2nd by half a point to Larsen at the reasonably strong Palma tournament, doing much better than predicted by rating.

- Finished second by half a point to Larsen again in the strong Monte Carlo tournament, again doing better than predicted by rating.

- Was about on par in his other 14 games.

I'm not saying who was better overall - just set your obvious biases aside, and focus on this year! The fact is, Petrosian had a wretched 1967 - this you can't deny. It didn't take a volume-worth of brilliant games from Botvinnik to overtake his rating; Petrosian even fell as low as #10 in the world for a month in 1968. Botvinnik was over the hill, but Petrosian was (for a year) out of form. What's the problem with that? Why do you refuse to see it?

Where is the black King going? Would ... 0-0-0 suffice at some point? Castling Kingside for black seems weak.

This a hugely tough position to evaluate, especially for us amateurs.

What I thought was a great advantage was his play to exchange the dark squared B's.