How bad were the old "GM's" really

Let me point out that the OP specified the time period "1700's to 1900's"

The 1930s are in the 1900s.

Btw, there's no way of knowing how strong players before ~1850 really were because with only a few exceptions because there are so few extant games, and many of those were "best" games. An exception is the LaBourdonnais-McDonnell matches. 

I have not done any rigorous studies of the games of the great players before Morphy but I have analysed many games from that period. I strongly suspect that Philidor was almost as strong as Morphy, but there's not really a good way of finding out because there are so few games, and we don't know the conditions those games were played in. La Bourdonnais and McDonnell were almost certainly better than Staunton, but I don't know how much better. 

I think an educated guess regarding the strength of Philidor, La Bourdonnais and McDonnell is 2200 for Philidor, 2100 for La Bourdonnais, and ~2000 for McDonnell. 

Jamie, let me respond by saying that "to" 1900s is before 1900s. I can see you love pointless arguments from your activity on the Star Trek and Global Warming threads.

An EXCELLENT ad hominem attack! Nicely timed!

I stand corrected.

I always have a point, and more often than not, I'm right.

Take a hike, faker. Comments made within the past two weeks are not the "ancient past."

Nice try, though.

Ylblai, your attack still doesn't make any sense to me. Nunn has clearly studied the classics, and yes, I can state with certainty that he has carefully analysed every game from the Karlsbad 1911 tournament.

I can state with near certainty that he did not look at just one tournament, but many from that period, including Hastings 1895, St. Petersburg 1914, NY 1924 and others. These are standard texts from that period. This is what Nunn said:

" Like most contemporary grandmasters, I was familiar with all the standard textbook examples from the early part of the century"[Emphasis added]

He goes on to show that he is familiar with the tournament books of the past:

"Although there are exceptions, tournament books from the early part of the century seem to be strong on flowery rhetoric but weak on pointing out mistakes."

http://theweekinchess.com/john-watson-reviews/historical-and-biographical-works-installment-3

I can state with confidence that John Nunn, as an editor at a major chess publishing firm, and as a grandmaster with a strong interest in the history of chess (as commented on by Edward Winter and Gary Kasparov, among others), analysed every game from several different tournaments of that period. That is not an extreme statement. I never claimed, for example,  that he analysed every game from every tournament. 

Even if I am wrong about the specifics there, which I doubt, I still have no clue why you have taken such a deep personal interest in trying to prove me wrong. 

Nunn's statements are clear. He believes that the old masters were not nearly as good as today's masters. 

Do you disagree with the statement made by Nunn, 

"It is quite clear that the Karlsbad players were far more prone to severe errors than contemporary players. Even the leading players made fairly frequent blunders."

And his general conclusion:

"To summarize, the old players were much worse than I expected. The blunders thrown up by Fritz were so awful that I looked at a considerable number of complete games 'by hand', wondering if the Fritz results really reflected the general standard of play. They did."

Here is the source image:

I do not know the provenance, but it is readily available as wallpaper.  A friend of mine modifed it with her Photoshop skills to include a Carmen Miranda headdress.

The image has been described as a warrior woman, Amazon, fantasy warrior, etc.  It appears to me to be an image of a strong warrior woman who has slain a dragon.  An apt chess metaphor.

I don't see how you could mistake the creature for an "earthworm."  Nor are the warrior's beasts (rather than "breats") particularly exaggerated, as so often happens in fantasy art.  The idea of a strong woman must be intimidating to you, as you are so quick to minimize the imagery.

The old GMs were so bad that they would easily crush anyone in this thread ! 

careful, not with that silly warrior above you. 

Here, yet another modern chess MASTER says that these old GMs were great players. Why does no one listen these people, who are better qualified to judge that some patzer starting this thread?

I have no doubt that a USCF 18xx would get pummeled buy the likes of Lasker, or even Chigorin. The people who claim otherwise are the same fools who think that they can, at the age of 17 with a 1200 rating, someday become a GM.

And this one:

And

Which of those four games were played by old masters and which were played by people who have posted here?

Rule: No fair looking up the games in databases. You may only look at the game scores themselves. You may use an engine to assist you in evaluating the quality of the games.

Han Solo: Let him have it. It's not wise to upset a Wookiee.

C-3PO: But sir, nobody worries about upsetting a droid.

Han Solo: That's 'cause droids don't pull people's arms out of their sockets when they lose. Wookiees are known to do that.

Staunton: 1 inaccuracies, 1 mistakes, 0 blunders, 17 average centipawn loss (inaccuracy Move #7, better was 0-0; mistake Move #18, better was Bxc5)

Popert: 2 inaccuracies, 3 mistakes, 0 blunders, 47 average centipawn loss

Staunton played a master level game.

Players before 1850 were bad.  Duh.

If Staunton played "master level" in that game, I am Komodo running on a super-computer built by a highly developed alien race.

Here is a game between two masters, White (2300) and Black (2600)

The computer scoring gives these masters -

White: 4 inaccuracies, 2 mistakes, 1 blunder, 37 average centipawn loss

Black: 1 inaccuracy, 0 mistakes, 1 blunders, 22 average centipawn loss

I'd call this a master-level game.  What about you?