Evolution of chess: Popularity of openings over time
randalolson.com
randalolson.com
I've never heard of Mahescandra, but Cochrane is the guy the famous Cochrane gambit in the Petroff is named after, where White sacrifices a piece on move 4 (1.e4 e5 2.Nf3 Nf6 3.Nxe5 d6 4.Nxf7).
He contributed to the development of the Indian Defence.
So what I would be interested to see from your data set is a relation between opening performance and its popularity. Did people stop playing the Pirc due to sub-par results compared to other openings at the time (like I imagine happened with the Vienna) or did it simply fall out of fashion? It would be interesting to know which lines always had good results, but just stopped being popular for whatever reason. They could be due for a revival.
Case 1: The Limburger Gambit was popular for a few decades, but then grandmasters started playing the Limburger Gambit Deferred instead, so it fell out of fashion, although it is still a perfectly good opening.
Case 2: The Limburger Gambit was popular for a few decades, but then a response was found that refuted the whole line. It was played in one famous game, after which everybody abandoned it.
As far as the data set is concerned, the difference between these two cases is a single game, so it's not going to show up in the stats.
For example, the King's Gambit hasn't really fallen out of favor despite the lack of long grandmaster games. The Falkbeer Countergambit (1.e4 e5 2.f4 d5) in particular has seen a revival as of late with the Nimzowitsch variation (3.exd5 c6!?). You might not see Carlsen and Anand playing it in tournament (mostly due to the risk-reward factor of having to solve complex positions over the board under time pressure), but they've almost certainly studied it with their team of coaches and researchers.
To comment on the Pirc: statistically, Black fares much worse with the Pirc in relationship to the most successful counter to 1.e4, the Sicilian defense (1...c5). From a gameplay perspective, Black has to commit much earlier with the Pirc than the Sicilian, since the Sicilian has about a billion variations starting as early as the second move.
Before you get too deep into openings, you should have a solid understanding of the strengths of individual pieces. This leads to a better understanding of why you'd want to put your pieces in certain places. It kind of explains the broad strokes of openings, without the little traps here and there. This is known as the Russian school of teaching.
Basically, learning from this direction, you can spend much less time studying openings. You might want to know about few common traps in common situations that you tend to use, but that's not the focus. And you'd be surprised at how well this works - barring a tiny number of games where you're caught out, your better understanding of the overall game will win out.
Essentially, overspecialising in opening repertoire at the novice level is a kind of arms race which only really works against other similar players. It's not a good long-run strategy.
Now if you like open games such as the King's or Evans Gambits (i.e., fashions of 100+ years ago) things will get tactically bloody pretty quickly and so gaining a knowledge of where the booby traps are will be prudent. But if your taste runs to semi-open games, say, you can limit your opening study to a relatively small number. I happen to like the Dutch Stonewall formation as black for example, and the precise move order for getting into a position I'm comfortable with doesn't require a lot of memorization.
Happily we live in a time when computers can not only entertain us in chess but also help us with learning chess. You can improve your tactical skills by studying a tactical positions card deck in Anki for example. Or you can work on a particular opening by setting the computer to always start games from a particular position. You can use that same starting position trick to train yourself in endgame play. The important thing is to find ways to keep the game fun while you improve your play.
This is not to say that opening study is not very important at higher levels, and if that upsets you in principle about the game, I totally understand. But it distresses me to see novices give up on chess because they are under the impression that at their level it's all about memorizing some killer opening shots.
Note that high-level Go play requires a lot of memorization too (joseki, life and death status of common shapes, etc.).
Yes, tactical lines do require more knowledge of concrete lines, because they are complicated to work out over the board. But at that point the memorisation should be a "summary shortcut" of your understanding or assessment of the position.
If it were about memorisation, what happens when both players reach the end of their memorised lines? If it's not mate, or one player being substantially better off (in which case, why did the other player memorise that line too), how do you proceed from there?
And that's where knowing an opening comes to the fore, the important part of the opening isn't the moves themselves, but how the game opens up to the middle-game. Understanding the types and structure of the middle-game that's derived from the opening is a far more valuable investment of time. For instance, knowing how to play with and against an isolated d-pawn - a significant number of opening variations lead to these kind of structures. Hedgehog structures, static double-pawn structures, backward pawns, outposts on an open file.
Knowing how to play a position is long term more valuable than memorising a routine of moves. Understanding over rote-repetition.
Granted, some positions are predominantly tactical, and those you need to calculate - either at the board, or before hand. Memorisation is a poor substitute for actual experience.
One of my proudest over-the-board achievements was understanding how to exploit the positional drawbacks of the Black side of a Stonewall Dutch. And beating a player 600-700 Elo stronger than me because I understood the White knight manoeuvre from f3-e5-d3, before exposing Black's backward e6-pawn by opening the centre with the f3 + e4 pawn advances. I spent a week trying to understand one model game of that opening, white's plan was logical, and the strategic aim of exposing the backward e6 pawn easy to understand and attempt.
So basically, my opening move would be classed as 'other' but really it is one of 1.d4, 1.e4, 1.c4 in terms of the classifications of this post.
I think it'd be interesting to try to combine all possible paths for an opening into a single count, but that would probably be complicated if multiple openings can be reached through the same path. (e.g., which opening would the shared path be assigned to?)
As an overall guide I think what you have done is fine, but I suspect something in the order of 10-20% of games might be subject to transpositions where the opening move isn't an accurate categorization.
1. Players who want to play Queen's Pawn opening but avoid certain lines in them start in an English instead.
2. Players who want to play Queen's Pawn or English openings but avoid certain lines in them start with 1. Nf3 instead.
For example, just after White plays 1.Nf3, the game is classified as A04, but after 1...d5 2.d4, it's now officially a D02, over in the Queen's Pawn category, just as it would have been if the game had started 1.d4 d5 2.Nf3.
Databases usually keep track of chess openings played by ECO code rather than by specific moves, exactly so that these transpositions are handled smoothly.
Popularity has not a lot to do with the openings themselves but with other things like a good book being published, or a popular match (like WC).
Another thing you have is that some variations are really popular, and have good results, but are at one point refuted by a single game. As a result of this, the variation dies. but remains to have very good statistics.
I don't really play chess anymore, but two decades ago, I played quite a bit. Much of the time, it was against a computer. I couldn't win. I finally found a book that really worked for me, and it taught me the "stonewall" approach, where you (playing white) advance the queen's pawn, lock up the game, and start maneuvering very tactically to restrict the movement of black's king and get a mate.
I found that this was the only way I could beat the computer - largely because it allowed me to think along a very few narrow lines (often involving a sacrifice), while the computer would get bogged down in useless searches. This was all in the late 90s, my guess is that it wouldn't work anymore.
So, I'm wondering if the surge in queen's pawn opening is the result of people being conditioned to play against computers? And it brings up another point - I've heard (man, I wish I could find a link to this theory on the web) that chess masters who lament the rise of computers actually aren't particularly bummed that computers can beat the strongest human chess players. They're bummed that the best human chess players are now playing a style that is heavily influenced by years of practice against a very specific style of opponent - a powerful computer that can't really make a "mistake". Young people have opportunities to train that never existed before, but because they don't train against stronger human players as often, some of the style of the game has been lost. I'm not (and never was) good enough at chess to know if this is true, but if anyone has an angle on it, please chime in!
Oh - by the way, a very satisfying ending here. I knew a very brilliant guy who I couldn't beat at chess in high school. After I read this "stonewall" book, I was all ready for him. I advanced queen's pawn, all read to lock it down and take away his advantage. He simply advanced his king's pawn, basically telling me, go ahead and take it. The wide open game against an inferior opponent was worth far more to him than a pawn.
Good for him, though not so good for me ;) That's the kind of thing you do when you're experienced playing against people rather than computers.
I don't think that the current popularity of 1.d4 is due to playing against computers. The main reason it is currently more popular than 1.e4 at the highest levels is that Black has found a very effective way to counter 1.e4 (the Berlin variation of the Ruy Lopez) that makes it difficult for White to achieve more than a draw. This high-level popularity then trickles down to lower levels.
It is definitely true that the style of play has changed somewhat due to computer engines, but it's not so much the result of playing against computers (top players generally don't find that very rewarding), but of analyzing with computers. You can play through a game or an opening and explore variations, with the computer constantly telling you what it thinks the best moves are and who is winning by how much. As a result, players become trained to evaluate positions closer to the way a computer would. One example is that computers don't mind grabbing material and defending an unpleasant position for a long time if they don't think that the opponent can break through. This has given players confidence to be more materialistic than they were in the past.
This also reminds me of a Martin Amos novel "the information" (based on the publication date, I'd guess I read it around the same time I was learning the stonewall attack). There's a section where one writer is determined to defeat his friend at everything (tennis, chess, a few others), and he hires people to help him.
The chess teacher, I believe, teaches him something that sounds like the stonewall defense, and reflects that it almost feels like he's teaching someone to cheat at chess rather than play it. The writer isn't cheating of course (at all), but I think it feels this way to the chess master/instructor because he's learning the stonewall because he doesn't really want to engage in the actual competition. He wants to sidestep it in order to win.
I'm not trying to knock the queen's pawn defense, more the way I (and this writer) were trying to use it. I'm sure queen's pawn openings can be very creative. But in my case, this is why I considered my buddy's play of the kind's pawn a "satisfying ending." I was (to use the tennis analogy) using a pusher's approach. When you watch two people playing a game, and it's clear that one person is trying to win by shutting down the game rather than really playing it, you tend to root for the person going for creative play.
Are there any squares never used after the first move?
Just what weight is given to the centre of the board after the first few moves?
This sort of information could be communicated really well with a view of the board, and the pieces expected to be in each square.
(I'm sure in the general sense games with a very large n aren't as I suppose a game could be played in perpetuity)
That's easily above 10^30 positions. 10^30 is a very low lower bound, too.
So, uh, no.
It's also not strictly exponential as n increases, pieces are removed from the board for example restricting the number of legal moves as the game progresses.
There's probably interesting solvable subsets up to large numbers of n, like maximum captures as the game progresses, or all games where there are zero captures or some such.
It's not a simple matter of calculating every possible theoretical legal or non-legal state of the board with all the pieces.
As the pawns are moved to make way for the back row the number of legal moves increases very quickly. For example if white plays d2-d3 then it frees the King, Queen and Bishop to move; 2 possible moves are removed and 8 are added.
This means that Chinook can play perfectly from the start position against any set of opposing moves, but if you play a move on Chinook's side that it wouldn't play for itself, the resulting position is probably not solved by Chinook.
An arbitrary position is in fact very unlikely to have been solved.
I don't know how much this is actually true though. That would also be a good thing to look over
However, except in cases of gross incompetence it doesn't lead to your queen being taken, it's just suboptimal. There are also plenty of exceptions to this rule, of course. The most obvious one is the main line of the Scandinavian Defense, 1.e4 d5 2.exd5 Qxd5. This isn't a grade-A opening but it's a solid B+ and occasionally gets used at the highest levels.