In Corr 2004 (Chessbase) I found a new defence to the Ruy Lopez. It is called the Kroll defence(named after Wladyslaw Krol, who's a correspondence player) and it starts with:

1. e4 e5 2. Nf3 Nc6 3. Bb5 a6 4. Ba4 Nf6 5. O-O Ng4?!

In my database (Corr 2004, Chessbase) I found 13 games played by Krol with this opening.

He scored +5 =3 -5 .

I have copied one of his games, with annotation of Roberto Alvarez

I hope you can follow it

:

(482237) Van Dijk,HLL (2261) - Krol,Wladyslaw (2288 ) [C78]

CM.2002.0.00170 IECG email, 13.02.2002

[Alvarez,Roberto]

**1.e4 e5 2.Nf3 Nc6 3.Bb5 a6 4.Ba4 Nf6 5.0–0 Ng4**?! A new variation in the ancient Ruy Lopez ? At first glance, I supposed this to be a notation mistake. But after seeing the continuation I am sure if this was a deliberate move ! We are in presence of the "Krol Defence" in the Spanish Ruy Lopez.

**6.h3** [6.c3 d5!? (6...b5 7.Bb3 Na5 8.Bc2 Nc6 9.d4 Qf6 10.h3 h5 11.a4 b4 12.d5 Nd8 13.Bg5 Qg6 14.Qd2 f6 15.Bh4 a5 16.Bg3 Nh6 17.Nh4 Qh7 (17...Qf7 18.f4 Ba6) 18.f4 Ba6 19.Re1 Bc5+ 20.Kh1 Nhf7 (20...Ndf7 21.f5 0–0) 21.f5 Rg8 (21...Nd6 22.Ng6) 22.Bf2 bxc3 23.Nxc3 Bxf2 24.Qxf2± Nb7 25.d6 c5 26.Bb3 Nfxd6 27.Bxg8 Qxg8 28.Qf3 Bc4 29.Qxh5+ Bf7 30.Qe2 c4 31.Rad1 Ra6 32.Qe3 Qh7 33.Nf3 Qh6 34.Qf2 Ke7 35.Re2 Qf4 36.Red2 1–0 Brueckner,J-Krol,W/IECG 2001) 7.Qe2 (7.exd5!?) 7...b5 8.exd5 Qxd5 9.Bb3 Qd6 10.h3 h5? 11.d4 Be7 12.hxg4 hxg4 13.Nxe5 Nxe5 14.Qxe5+-; 6.d4 h5 (6...b5!?) 7.c3 (7.d5 Ne7 8.h3 b5 9.Bb3 d6 10.a4 Rb8 11.axb5 axb5 12.Qd3 Ng6 13.Nc3 Bd7 14.Ra7 Nf4 15.Bxf4 exf4 16.Qd4 Be7 17.Rfa1 Ne5 18.Nxe5 Bf6 19.Nxf7 Bxd4 20.Nxd8 Bxa7 21.Nc6 Bxc6 22.Rxa7 Bd7÷ 0–1 Sacerdotali,S-Krol,W/IECG 2001/Telechess CBM 87 (57)) 7...Qe7 8.h3 d6 9.c4 exd4 10.Nxd4 Qe5 11.f4 Qc5 12.b4 Qb6 13.hxg4 Bxg4 14.Qd3 Be2 15.Qxe2 Qxd4+ 16.Qe3 Qxc4 (16...Qxa1 17.Nc3 a5 18.Ba3 Qxf1+ 19.Kxf1 axb4 20.Bxc6+ bxc6 21.Bxb4+-) 17.Bd2 Qe6 18.Rc1 Kd8 19.Nc3 f5 20.Qf3 Nd4 21.Qd3 b5 22.Qxd4 bxa4 23.exf5 Qxf5 24.Nd5 1–0 Schoonhoven,J-Krol,W/IECG 2001/Telechess CBM 87 (24)]

**6...h5**!? A piece sacrifice, in order to mount an attack over the h-file. The motif is similar to the one used in the Exchange Variation of the Ruy Lopez (with a Bischop at g4 instead of the Night). 7.c3 [White shall not take the "gift". 7.hxg4? hxg4 8.c3 (8.Nh2? Qh4) 8...gxf3 9.Qxf3 Qh4–+; 7.d4 exd4 (7...Qf6? 8.Nc3) 8.hxg4 hxg4 9.Ng5 Bd6 (9...f6 10.Qxg4 fxg5 11.Bxg5 d6 12.Bxd8 Bxg4 13.Bxc7 b5 14.Bb3 Rc8 15.Bb6 Rb8 16.Bc7 Rb7) 10.e5 (10.Qxg4 Bh2+ 11.Kh1 d5 12.Qf3 Qxg5 13.Bxg5 Bg3+=; 10.f4 Bc5) 10...Bxe5 11.Re1 Kf8 12.Bxc6 Bh2+ 13.Kf1 dxc6; 7.Nc3]

**7...Bc5 8.d4 Ba7 9.hxg4 hxg4 10.Ng5** [10.Bg5 f6 11.Nxe5 Nxe5 12.dxe5 fxg5 13.Qxg4 b5 14.Bb3 d5 15.Qg3 dxe4±]

**10...d6 11.Bb3 Qf6 12.Nxf7** [12.Bxf7+ Ke7 13.Re1 Qh6 14.Kf1 exd4÷]

**12...Rh5 13.Bg5** [13.Ng5 g6 14.Bg8 exd4 (14...Qh8!? 15.Bh7 Rxh7 16.Nxh7 Qxh7 17.Be3 Be6!) 15.Qb3 Nd8 16.Bh7 Nf7 17.e5 dxe5 18.cxd4 exd4 19.Nxf7 Qxf7 20.Bg8 Qxb3 21.Bxb3 Bf5 22.Nd2 0–0–0µ 1–0 Martin,M-Krol,W/IECG 2001/Telechess CBM 87 (47)]

**13...Rxg5! 14.Nxg5 Qxg5** Now Black is only an exchange down.

**15.Qd2** White invites to exchange queens, but Black refuses : the h-file, open, invites to an attack with the heavy pieces. [15.Qd3 Bd7 with idea of castling queenside.]

**15...Qf6** [15...Qxd2 16.Nxd2 exd4 17.Kh2 Bd7 18.Kg3 0–0–0©]

**16.Bd5 Bd7 17.Qe2** Meanwhile, White's queenside remains undeveloped... Besides, the queen takes the "flight square" e2 for White's king. [17.f4? exd4]

**17...0–0–0 18.Bxc6** Everyone would expect capturing on c6, recoving the piece, but Mr.Krol thinks different...

**18...Qh4**!!–+ A wonderful move, which decides the game in Black's favour.

**19.g3** [19.f4? g3–+; 19.Bxd7+ Kxd7 20.Qc4 Rh8–+; 19.Bxb7+ Kxb7 20.g3 Qh3–+]

**19...Qh3 20.Bxd7+ Kxd7** Better than recapturing with the rook, because its belongs to h8.

**21.Rd1 Rh8 22.f4 exd4 23.Qg2** [23.cxd4 Qxg3+ 24.Qg2 Bxd4+ 25.Rxd4 Qe1+ 26.Qf1 Rh1+!]

**23...dxc3+ 24.Kf1 cxb2** [24...cxb2 25.Qxh3 Rxh3 26.Nc3 bxa1Q 27.Rxa1 Rh1+ 28.Ke2 Rxa1–+]

**0–1**Does someone know if this line is playable for black??