Why isn't Pirc Defence detected by lichess?

Sure, of course 1.e4 d6 is most often a Pirc. I never denied that. I only denied that it was always classified as a Pirc by chessgames.com, which you originally suggested.

From post #5:

"But Chessgames.com, that should be norm in this case, lists everything that opens with 1. e4 d6 as Pirc"

At any rate, that's not so important.

Like I said, sure, most sites do end up just picking one of the opening designations, and like you don't really care which it is.
That's fine, but for the reasons I gave is less helpful for study.

Again, as with all things that are just about terminology, neither scheme is "wrong", and they are just more or less useful for different purposes, and make some people happy and some people not.

You like the scheme on chessgames.com, and don't like it here. I like the one used here and don't like the one on chessgames.com.

Neither is wrong, but neither can make everyone happy. Just the way the world works :)

Actually going for King's Pawn Opening (B00) in this case is wrong. If you go for one, you go for one most used instead going for one used very rarely. And this isn't about preferred designation per website, it's simply about right designations.

Openings are not designated website specific, names yes, number not. 1, b4 can be called Uncommon opening, Polish attack, Orangutan attack and I'm certain there are couple more, BUT it's always designated A00, A06, A04. Likewise, goes for all websites that use Encyclopedia of Chess Openings (ECO) names for openings, so you really don't have different schemes here or on chessgames.com.

The current system of exact move order is a lot easier to work with, and recognising transpositions is fairly tricky. I'm not sure if it's planned, but I'm personally fine with the current system in light of OneOfTheQ's rather informative argument. My only issue is with being able to find certain games on the site when categorised by opening, but it's not quite as major an issue for me, but the search system needs an overhaul, anyway.

Also, Soltis' Beating the Bongcloud is indubitably the most valuable addition to my literary chess arsenal.

@Shashist:

I think you misunderstand what I'm saying. That's probably on me for not being clear enough.

I'm not saying that the names are chosen by sites, as if some sites were to start calling 1.b4 a5!? the OneOfTheQ defense.

I'm saying that different sites choose how to deal with transpositions. With transpositions through multiple opening openings or with move orders that arise in exactly the same position from different openings, as in my original post, one could choose to call them any of the applicable openings, and have some decent reason to.

In that sense, there are different schemes here and on chessgames.com. It's not that the names associated with specific ECO codes are different between the sites (although that can happen, as you pointed out). It's that transpositions are handled differently.

Handling transpositions differently is neither right nor wrong. Sure, sometimes with openings that haven't transposed there is an unambiguous way. 1.b4 is indeed always the Polish/Orangutan/Sokolsky or whatever, at least at that point, because there are no transpositional possibilities after 1 move :)

However after 1.b4 c5?? 2.e4??, is that an Orangutan gone wrong (or if we're being really perverse, a declined Birmingham Gambit, since apparently that's what 1...c5?? is) or a Sicilian Wing Gambit?

One is A00, and the other is B20. Neither is wrong.

For me it's more informative to stick with the Orangutan classification, than to classify it as the wing gambit, but we each expect different things from the classification.

Again, neither is inherently right or wrong.

We're talking about the scheme we use to categorize things. Schemes like that are by their nature not right or wrong, they're just more or less useful. Sure, you can adopt ECO and chessgames.com's handling of transpositions as your gold standard, and that's fine, but doesn't make it objectively "right".

It's just one scheme, and if that's the most helpful one for you, that's great! If I want to use ECO and exact move order instead of transpositions, that's not less "right" than your approach, just different and more useful for me.

It's like I'm trying to support a bunch of items on a stand, and you're trying to fit the same items into a container. I categorize them by weight, because that's what matters to me. You categorize them by volume, because that's what matters to you. Are you more "right" than I am? Of course not.

Same thing here. I care about the exact move orders used, so I categorize my games by the ECO associated with the exact move order.

You care about the thematic/defining position reached out of the opening, and categorize them by the ECO of the most common opening associated with that position.

Neither is wrong, they just serve different purposes.

Also, just to show that I'm not just citing weird examples that don't actually occur in any existing software or site, in the French Exchange/QGA example I cited in my first post, the free GUI Arena switches the ECO to D20 for the QGA after 5.Bxc4 in the French Exchange move order.

365chess.com, my preferred online database, keeps the ECO of C01, for the French Exchange.

Different schemes, neither right or wrong. Again, they're just differently useful. You like one, I like the other. Neither is objectively wrong. :)

@AdmiralA:

That is most important. Meeting Ke2 over the board is quite difficult :)

Also, for the purists out there, I do realize that in the line 1.b4 c5 2.e4, neither 1...c5 nor 2.e4 are actually blunders, or even mistakes, really. I was just being theatrical with my double question marks :)

I played Pirc Defence anf it detected very well for me