an ordinary chessplayer wrote on 02/15/22 at 04:41:46:
I have played the Paris Defense quite a bit, more often from the Philidor move order, 1.e4 e5 2.Nf3 d6 3.Bc4 Nc6!?, where it seems to confuse 3.Bc4 players.
Rodzynski - Alekhine, Paris 1913:
https://www.chessgames.com/perl/chessgame?gid=1011850 Most strong players play 4.c3 against me, which doesn't worry me at all. I go 4...g6!?. A good source there is Taylor/Hayward (2009)
Play the Ponziani (1.e4 e5 2.Nf3 Nc6 3.c3 d6 4.Bc4 is their move order). Most weak players play 4.Nc3, which also doesn't worry me. I go 4...Be6!?. The critical move is 4.d4 and if 4...exd4 5.c3! I have only faced this once and replied 5...d3!?. I ended up losing, but not because of the opening, where I was quite close to equality.
Most Philidor sources don't cover 3...Nc6, e.g. Bauer/2006 gives "?!" and says it is out of scope. Two Philidor sources that cover it are Heiling/1987 and Cermak/1993. They give different answers to 4.d4. Heiling gives only 4...exd4, quoting Glek - Dreev which went 5.c3 Na5!?. I'm not sure but I suspect Heiling's notes to that game are taken from the Informator. Cermak gives only 4...Bg4, which is not my cup of tea, and seems to have mostly cribbed from ECO. Cermak's book is interesting because he sometimes gives original analysis, unfortunately many of his suggestions are not correct. His engine in 1993 was not strong at all.
Glek - Dreev, SSSR 1985:
https://www.chessgames.com/perl/chessgame?gid=1038882 I did notice the new "trend" 4...Nf6 but haven't had time to analyze it closely. The dry line with 5.dxe5 wouldn't bother me, defending a slight white initiative is par for the course in the Philidor.
I'm interested in new/different approaches to 4.c3 (Dubov's 4...f5) and against 4.Nc3 then 4...Na5 which I found with an engine but it makes sense, White has made it difficult for himself to control d4 so Black would like to play ...c5 there was a game with it Grund-Romanov (a couple of 2400s) in 2002, it's not on chessgames but is on 365chess which requires an account but I've gotten maybe one email from them in a decade.
Speaking of ...f5, in another critical line 4.0-0 Be7 5.d4 Nf6 6.d5 Nb8 I've found a possible path, of course depending on White's moves, to a freer position and possible equality for Black after ...0-0, ...Kh8, ...Ng8 and ...f5 but I have lots more investigating to do, I've been looking into it after 7.Nc3 but it might not be so well suited after 7. Bd3 (as played in the blitz game Anand-Ivanchuk from 2017)
BTW I learned about the Alekhine game from the Seirawan book "Take My Rooks" but he had a simpler path to a winning position at one point with the simple ...Be6 (which is sometimes a good move in general in the Paris Defense e.g. against 4.h3?! which I've seen a lot as an amateur)
EDIT: So I found the idea of 7.Nc3 0-0 and the ...Kh8, ...Ng8 and ...f5 by tinkering around with SF14 but interestingly I've now found a game lost by Bernard Cafferty playing White against this idea in the 1959 British Championship (Golombek, Haygarth and Penrose tied for first):
https://www.chessgames.com/perl/chessgame?gid=1161308 Upon closer inspection even in the line 4.0-0 Be7 5.d4 Nf6 6.d5 Nb8 7.Bd3 a future ...f5 can be a factor e.g. if White follows the same erroneous path as Anand did against Ivanchuk: 7...0-0 8.c4?! Nc5 9.Nc3 Nxd3 10.Qxd3 O-O 11.Nd2?! Nh5 12.g3 g6 13.b4 f5, I guess that White allowing the exchange of his bad LSB made it easier for Black to acheive ...f5, which is also in the offing after 11.c5 and then either 11...Nh5 or 11...Ne8. Against 11.Ne1 Black plays 11...Nfd7 to respond to 12.f4?! exf4 13.Bxf4 with 13...Bf6. Against 12.Be3 Black can play 12...Bg5, and if instead 12. Qd2 to prevent that, or 12.Qe2, again Black has 12...f5