Yes, I am even a little higher rated and have played numerous (low rated GMs) in tournament play. I do think they analyze more than 1-3 times per game.

The main thing commentators here are missing is that GMs have more confidence and do not repeat their analysis, but amateurs (strong club players included) typically re-analyze the same lines over and over. That alone would account for far stronger play with fewer moves considered, if you count the same move multiple times, which you should!

Also, Jonathan Rowson (Scottish GM - peak about 2600) describes his training matches with Mickey Adams (peak #3 or so in world - 2760), and says pretty much the same thing. Most of the time he asked “what about this line I rejected”, the answer was usually “I hadn’t considered that”.

> The only time when GM will definitely analyze more lines than an amateur is in a highly tactical position

Those critical moments are a big part of the difference between a GM and a good club player though. If a GM was somehow handicapped to not calculate such tactics, I think lesser players would be able to draw games against GMs much more often.

I agree that GMs can avoid calculation in many positions (e.g. openings as you said), but the value of broader and deeper calculation is still huge in chess.

But it does mean they thought about at least as much as they verbalised.

Much of what's happening is less like 'calculations in the back of their head' and more like 'pattern recognition'. Chess masters are recalling ideas and motifs (not necessarily actual positions) from earlier games or practice or study, and this recall is allowing them to either prune the decision tree or prioritize investigating more fruitful branches faster than amateur players, who have to actually calculate things that are instantly 'seen' by the better players.

This is a known thing among chess players, and even low-skilled players do it to some extent. A newbie to chess can (and almost every teacher will say 'should') work their pattern recognition by just solving tactical chess puzzles and very quickly improve at spotting things like one or two move checkmate patterns or forks or pins or whatever.

It's more of a memory thing than subconscious calculation.

But that's not what it's saying right? The quote says grandmasters and amateurs analyze the same number of moves. I mean it would kind of make more sense how you are interpreting it but is that actually what the quote is saying?

Meaning, you analyse 100 moves will not be the same set of GM 100 moves. And GM work on better 100 moves than yours. If you pick the moves that GM not thinking of, you likely get crushed because those moves are very inferior moves that GM already can see the outcome without the need to consider. Meanwhile if GM takes on moves you dont consider, you get crushed too. The likely silver lining will be you picking the same moves as GM. But up to a point, his depths will crushed you either you pick a wrong moves by mistake, or he out think you a few step more. Is like a math student who do same amount of steps as yours, but you look at his answer in awe because better and succint...and even confused as how it reach that. TBF, today AlphaGo engine will crush Stockfish and any GM too.

They have tree pruning heuristics. Probably all human masters of any craft have them. They're precise to some given extent, after which tacit/embodied knowledge, aesthetics and vibes take over.

I strongly believe some people are inherently good at chess but no one is inherently bad. If you're interested enough to comment this, play one 5-minute game a day on lichess. Start with the lowest setting but do it every day, maybe in the morning with coffee. You might not win a single game the first year but slowly you'll improve. When you're winning more, move up a level. Sometimes do the puzzles. Give it five years and you'll be able to beat almost anyone you meet and, better yet, you'll know the answer to your question based on your own experience.

> where does the pattern matching stop and strategy starts or it's one and the same?

It's not one and the same, but strategy patterns are definitely a thing too.

There are:

- tactical patterns (e.g. "back rank checkmate", or "pair of pieces that can be forked by a pawn");

- strategy patterns (e.g. "knights are good in closed positions", or "in a same-colour bishop endgame, put your pawns on the colour opposite to the bishops").

There's also calculation ability which also partly relies on patterns one has seen before.

I became significantly better at chess through two simple things:

1. Take a little extra time to visualize what will happen after you make a move. Will the piece be vulnerable? Does moving that piece leave a different piece vulnerable? I'd argue the biggest beginner mistake is not seeing that their move leaves a different piece vulnerable to being captured.

2. Don't move your queen into the board until after you move both bishops. This simple rule of thumb makes it far less likely you will lose your queen early, and it forces you to do a lot of other useful things (develop your pieces, control a portion of the board, etc).

Disclaimer: I am not good at chess, but when I played semi-regularly these helped me hold my own against other beginners.

No, a grandmaster can also consider moves way faster than an amateur. Watch Hikaru Nakamura solve chess puzzles [1]. He has already solved the puzzle and moved on to the next one before an amateur can even see the pieces on the board.

[1] https://youtu.be/4EfSymvT59M

It's not a tree since you have transpositions. It's a directed graph, since it has cycles.

No, I watch plenty of "regular" GMs, as well as some IMs and even FMs who all consider way more moves/positions than I do.

After some digging it goes back to Adriaan de Groot (in 1946).

[1] (2011) has a summary in the introduction:

   de Groot presented chess players of varying skill, including some of the best players of the time, with an unfamiliar position and asked them to think aloud as they analyzed the position and chose what move they would make. de Groot found that, contrary to popular belief, the strongest players did not think further ahead than weaker players. World-class Grandmasters (GMs) searched at a similar depth and considered a similar number of options as mere chess experts. 

As [1] is also a somewhat reproduction of the original study, you can take it directly.

    Six Grandmasters, five International Masters, six Experts, and five Class A players completed the think-aloud procedure for two chess positions. Findings indicate that Grandmasters and International Masters search more quickly than Experts and Class A players, and that both groups today search substantially faster than players in previous studies. The findings, however, support de Groot’s overall conclusions and are consistent with predictions made by pattern recognition models.

Section 3 Table 2 is probably most interesting, they had 2 board positions and 2 groups sectioned:

Masters (2350+) | Intermediates (1800-2200)

(Mean values only, i tried inlcuding stddev but it was hard to read)

Positions Evaluated (A): 145.3 | 138.6

Positions Evaluated (B): 216.6 | 190.6

---

Max Depth (A): 11.7 | 9.4

Max Depth (B): 14.1 | 12.0

---

Mean Depth (A): 4.1 | 3.3

Mean Depth (B): 4.9 | 4.2

What i found interesting was that the "intermediate" group had a higher number of "base moves" they evaluated (eg Pos A: 5.6 | 8.6).

The previous studies (de Groot and another rperoduction from 1998) had "Nodes visited" for position A at 51.6 | 34.3 and 48.3 | 40.1 so similarly close together as the new ones, but much lower. (depending on your definition on "similarly close together")

[1] https://onlinelibrary.wiley.com/doi/10.1111/j.1551-6709.2011...