The above chart (based on August 2017 TWIC data) was recently highlighted in a ChessBase news article. As usual, the best way to view any statistics is with a critical eye. With that in mind, here are some observations related to my personal repertoire, which I know best, and some other opening trends that are highlighted.
At first I was surprised at the high popularity of the Caro-Kann (#4), my primary defense to 1. e4, but after you start adding up the various Sicilian variations, it makes more sense and does not in fact represent a big surge for the Caro-Kann. The main point is that the Caro-Kann is reliably popular and a solid choice at the professional level (more on that point below), to the point of beating out the most popular variation (Najdorf) of the Sicilian.
Likewise with the Slav (#7), my primary defense to 1. d4, but that actually seems to be more logical as a separate category in the queen pawn opening complex, with the main 1...Nf6 choices ahead of it. It's interesting to note that it does beat out the more historically popular Queen's Gambit Declined, but only (I expect) if you include the Semi-Slav complex of openings, which I don't have in my repertoire.
On the White side, it was nice to see the English well represented, with various main trunks taking up 4 of the top 20 spaces. This makes sense, as it's a great must-win opening (said only partly jokingly). It's worth noting that the reply 1...e6 is on the list, as in opening manuals it's often treated as a sideline (if at all). While there are a lot of transpositional possibilities, it's something that every English player should look at.
A couple of general observations on the list:
- The absence of the Ruy Lopez / Spanish Game is not completely shocking, if you've been paying attention to the top-level games over the last couple of years, but is still very interesting as a novel historical development. Basically the top White players seem to have switched to the Giuoco Piano (#18) as holding better prospects for advantage. Seeing the Caro-Kann at #4 and the Ruy Lopez nowhere on the list is still a bit weird, at least for those of us who have been playing for more than a decade. The "Spanish Torture" seems to have lost its edge.
- The #1 place for the Reti in my opinion is a reflection of the trend at the top, especially with players like Carlsen and Kramnik, to adopt a meta-strategy of "just playing chess" and seeking to win by relying on a deeper understanding of their game, rather than trying to fight it out in a theoretical duel. This is a common idea at any level, actually, as the strategy seeks to take away the advantage of "free good moves" that a lower-rated player is offered by going into a well-prepared and analyzed line for 15-20 moves. The caveat, of course, is that you actually do have to have superior knowledge of the resulting position-types, even if things like exact move orders are not always crucial, or there is a lack of forcing moves.
- I have to admit I was surprised by the continuing popularity of the Modern Defence (#20), as I thought its peak time was past. On the other hand it's a flexible choice, can be played in response to pretty much any White first move, and has the advantage noted above of being less forcing and more favorable to someone who knows the resulting positions and their requirements well.
- In general, I tend to look at the "top openings" lists as indications of what master-level players consider to be completely solid openings that will yield the best chance for an advantage and/or counter-play. Openings which are viewed as now being too drawish (the Ruy Lopez now, along with the Petroff) drop off in use as a result, but this lack of professional popularity should by no means influence amateur opening choice, when the openings in question are actually too solid rather than questionable.