My database shows I first played the Bird Opening in 1973, a year after the Fischer-Spassky Match, when I became serious with chess. Around 1980-81 I became enamored with the following line: 1 f4 d5 2 Nf3 Nf6 3 e3 g6 4 Be2 Bg7 5 O-O O-O 6 d3 c5 7 Qe1 Nc6 8 Nc3! I have played 8 Nc3 hundreds, maybe a thousand, times! I found 8 Nc3 on my own, and developed my own theory (before chess engines and databases).
I wrote about this variation, and my games with it, in APCT (American Postal Chess Tournaments) magazine (now defunct). I shared analysis and games at Chessville.com too. Note that website is no longer around.
Vanity had me call this variation "Hayward Bird" back then. For years I have shared my old analysis (mostly games) at:
Initially, with my return to playing the Bird Opening, I planned to play my old 8 Nc3 line. This approach has a somewhat positional quality, if both sides play well, but for personal reasons, I wanted something more aggressive and provocative with my return to the Bird Opening. My core recommendation for the future will center on the Christmas Tree formation against this Gruenfeld response.
I put a large effort into organizing my 8 Nc3 games into ChessBase analysis lines. The following analysis covers only the critical 8..d4 from Black, and then 9 Nd1! was my pet response. None of the following CB lines have been checked with a chess engine, so use with a little caution, and do your own research.
This first line features 9..dxe3 which was the most popular response against me.
At first, 9..Nb4 looks strong, but 10 Nxd4! is a strong answer. A critical line showing 9 Nd1 works!
Neither 9..Ng4 nor 9..Bg4 is worrisome.
Whenever I got in e4, which is easy against 9..Re8, I was happy.
White gets in a quick e4 against 9..Nd5 too.
White gets the desired e4 against 9..e5 too.
Here 9..Bf5 and 9..Bd7 are covered.
Quick queen moves allows White to play e4 with the desired formation.
To be honest, I have never understood the motivation to play positional moves like 9..b5. I think White gets pleasant kingside attacking prospects.
I hope a reader will champion my old 8 Nc3, and find my games useful in their quest. Good Chess! Keith