I have seen lists that named Zukertort as an Unofficial World Champion. And others that didn't. That's what comes of the list being unofficial.

If we count only the years 1886-1888 (when he died), I would NOT consider him one of the greatest players not to be World Champion. Nothing he did in those years suggests that.

But, what about the obvious point about players trying to protect their ratings by declining draws against lower-rated players? I'm not sure, to be honest, what point Sally Simpson is trying to make regarding NY 1924. Yes, Lasker and Capablanca had little to play for in the final round, but they nevertheless went for wins anyway. What does that prove though?

(Incidentally, Capa should have LOST his last round game but turned it around and won anyway. Not relevant to this posting though)

Well, your standard was which players stood above all but one player. Tarrasch and Korchnoi certainly did that.

I don't know if there's a single player candidate, but I think most players could agree on a Top 10 (in no particular order). There's certainly a practical point to the exercise. People tend to do a serious study only of players who actually became World Champion, however briefly, when in fact there are some non-champions deserving of serious study also.

Glad that's settled! :-) I'm fond of Larsen vs Petrosian, 1966

How do you feel about this game from this past January?

Aronian vs Carlsen, 2017

Putting aside ranking the non-champs by their best games, how about ranking them by how they play when they're not in form? I wrote this a dozen years ago:

<Rubinstein and Korchnoi tend to show up at the top of lists of the strongest non-champs. I think if you were going to choose between them based on their best games you would prefer Rubinstein. The King's Gambit against Hromadka, the counterattack on Thomas at Hastings, the wins over Capablanca and Lasker, the classic against Rotlewi are among my favorite games ever played. But if you were trying to figure out who was stronger day in and day out, I am sure you would pick Korchnoi.>

In support of that, I said:

<Look at this game, from Rubinstein's annus mirabulus:

Rubinstein vs Spielmann, 1912

It's a fine game by Spielmann, but white is positionally dead by move 15 and resigns at move 32. I can't remember a game in which Capablanca or Lasker just gets over-run like that.

Here's a famous loss to Alekhine:

Rubinstein vs Alekhine, 1926

A wonderful combination by Alekhine, but again white is busted inside of 20 moves.

A lot of Rubinstein's losses were classics, but I think because he tended to play very rationally and logically, rather than because he was very hard to beat. He didn't have the "smell" for danger that Capablanca was famous for, and he didn't have the slipperiness and stubborness and sheer orneriness that made defeating Lasker or Capablanca such an ordeal. Reti said something like chess was an acquired language for Rubinstein (he learned it relatively late in life) while for Capablanca it was his mother tongue. I have the London 1922 tournament book, when Capa was at his absolute peak. He never seemed to get in the slightest trouble, except via his own carelessness (as against Morrison). Rubinstein played some fine games there, but he doesn't exude power like Capablanca does.

I think Rubinstein just had bad days (he was having visible mental problems as early as 1912), and I think he was also a fatalist -- he believed in the game more than in himself. If things started going badly he seemed to expect to lose.>

Glad that's settled! :-)>