Dilworth Variation, it's not for the faint of heart

     Unless they're a peddler of opening books, most titled players advise amateurs not to spend a lot of time studying openings because time is better spent on tactics, middlegames, endgames, strategic concepts etc., etc. 

     Take a look at game below the master level and you'll see they don't go much beyond 6-8 book moves. And, I remember the time my young opponent blitzed out 20 or so opening moves against my Sicilian. Finally, when he sank into deep thought I knew he was at the end of his book knowledge. A few moves later he blundered and lost. In the post mortem I got a lecture about my move (the one that made him stop and think) being a bad one. The reason...it wasn't what Fischer played. My question was, if the move was so bad why didn't he refute it? I got a blank stare. 

     For us chess putterers, a general overview of openings should be sufficient. And, as for making your opponent think on his own and playing tactical tricks on him because chess is supposed to be 99% tactics...well, we are non-masters because we don't think very well on our own and our tactical vision is third string...unless, perhaps, we are doing tactical exercises and are told there's a mate in three or some such. There's nobody to tell us that during a game. That's why our chess is so dreadful. 

     The Dilworth Variation of the Ruy Lopez is one of the few opening variations named after an amateur player. Vernon Dilworth (September 16, 1916 - October 9, 2004, 88 years old) was a railway clerk who experimented with the line in the years of 1939-1941 in correspondence games, and then published some of his analysis in Chess magazine. 

     His variation got recognition when, even though it was unsuccessful, Botvinnik played the variation against Vasily Smyslov in the 1943-44 Moscow Championship. In more modern times, although today it's not often seen, players like Larsen, Ivanchuk, Short, Leko and Yusupov have played it. 

     The Dilworth is one of the most interesting variations of the Ruy Lopez. Black gives up a B and a N for R and P, or maybe two, in the hopes of launching an attack on white's K. If White is successful in fending off the attack the result is usually a very complicated ending which theory considers to be about equal. 

     Just for fun I let Stockfish 15 work on the Dilworth (the position after 11...Nxf2) for 45 minutes and its evaluation was slightly less than half a P in white's favor, i.e. equal. It should be noted that being equal does not mean drawn. 

     The following game is an early example of Dilworth's experimentation and it shows the complexities of his variation. It's certainly not for the faint of heart. 

[Event "Correspondence"] [Site ""] [Date "1941.??.??"] [Round "?"] [White "Estelles"] [Black "Vernon Dilworth"] [Result "0-1"] [ECO "C82"] [Annotator "Stockfish 15"] [PlyCount "48"] [EventDate "1941.??.??"] {Open Ruy Lopez: Dilworth Variation} 1. e4 e5 2. Nf3 Nc6 3. Bb5 a6 4. Ba4 Nf6 5. O-O Nxe4 {The Open Variation. Bent Larsen suggested that it was the only correct way for black to play against the Ruy Lopez.} 6. d4 b5 7. Bb3 d5 8. dxe5 Be6 {White now has a variety of options, including 9.c3, 9.Be3, 9.Qe2 and 9.Nbd2.} 9. c3 {This is the classical line.} Bc5 {The main line is 9...Be7, but this is the most aggressive.} 10. Nbd2 O-O 11. Bc2 {This is the best. Now black must meet the attack on e4. He has two main possibilities: 11...f5 and 11...Bf5, both of which aim to maintain the strong point on e4.} (11. Nxe4 dxe4 12. Ng5 {He could also exchange Qs first.} Bxb3 {Now the position is equal after 13.axb3, but} 13. Qxb3 {This logical at first glance move as played in Tindall,B (2190)-Korneev,O (2565) Jakarta 1997 is a serious mistake.} e3 14. Ne4 exf2+ 15. Nxf2 Nxe5 {and black is winning.}) 11... Nxf2 {The Dilworth Variation.} (11... Nxd2 12. Bxd2 Bg4 13. Bf4 Re8 14. Qd3 g6 15. Rfe1 Bf5 16. Qd2 Bxc2 17. Qxc2 {White;s better, but in Mackenzie,G-Weiss,M Frankfurt 1887, black salvaged a draw.}) (11... Bxf2+ {would result in about equal chances after} 12. Rxf2 Nxf2 13. Kxf2 f6) 12. Qe2 {Of course, the only correct move is 12.Rxf2} (12. Rxf2 Bxf2+ 13. Kxf2 f6 14. Nf1 fxe5 15. Kg1 Bg4 16. Ne3 Be6 17. b3 d4 18. cxd4 Nxd4 19. Nxd4 Qxd4 20. Rb1 Rad8 21. Qe2 Bf5 22. Bb2 Qc5 23. Bxf5 Rxf5 24. h3 {This position is evaluated as being equal.}) 12... f6 {[%mdl 8192] Very weak.} (12... Ng4+ {This move is hard to meet as after} 13. Kh1 (13. Nd4 { is not at all good.} Qh4 14. N2f3 Bxd4+ 15. cxd4 Nxd4 16. Qd2 Nxf3+ 17. gxf3 Nxe5 {and black should win.}) 13... Ne3 {forking the B and R assure black os the advantage.}) 13. exf6 (13. Rxf2 {is less good.} fxe5 14. Nb3 Bxf2+ 15. Qxf2 e4 16. Qe1 Qd6 17. Nfd4 {with equal chances.}) 13... Qxf6 {Bad move! White now stands better.} (13... Ng4+ {was his best move.} 14. Kh1 Qd7 (14... Ne3 { does not work in this line.} 15. Nb3 Qxf6 (15... Nxf1 16. Qxe6+ Rf7 17. Bxh7+ { wins}) 16. Bxe3 Bxe3 17. Qxe3 {White is winning.}) 15. Nb3 Bd6 16. fxg7 Kxg7 17. Bg5 {and white is slightly better.}) 14. Rxf2 {This is not really a blunder that loses the game, but now black is back on the attack. White needed to play 14.Nb3} (14. Nb3 {It's understandable that white missed this because now play becomes fast and furious!} Nh3+ 15. Kh1 Bd6 16. gxh3 Bxh3 17. Qd3 Bxf1 18. Qxh7+ Kf7 19. Qh5+ g6 20. Qh7+ Ke8 21. Bxg6+ Rf7 22. Bf4 {A hard move to find.} (22. Bxf7+ Qxf7 23. Qxf7+ Kxf7 {is unclear.}) 22... Be2 23. Ng5 Ne5 24. Nxf7 Nxg6 25. Nxd6+ cxd6 26. Nd4 {Another hard move to find!} Nxf4 27. Rg1 Ne6 28. Nxe2 Qf3+ 29. Rg2 {White is slightly better.}) 14... Rae8 15. Qd3 g6 { Better was 15...Bxf2+ first.} 16. Qf1 {The only move.} Bg4 17. Nd4 {[%mdl 8192] This move looks quite natural, but it loses quickly. Either 17.Bb3 or 17.h3 would have kept the chances equal.} (17. h3 h5 18. Bb3 (18. hxg4 hxg4 19. Nd4 { loses. Better is 19.Bb3 when black's advantage is minimal.} Qh4 20. Rxf8+ Rxf8 21. Qe2 Nxd4 22. cxd4 Bxd4+ {wins easily}) 18... Qd6 19. Kh1 {with an unclear situation.}) 17... Nxd4 {[%mdl 512] A tactical fly in the ointment.} 18. Rxf6 ( 18. cxd4 {is no better.} Qxd4 19. Nf3 Rxf3 20. gxf3 Bxf3 {thid id no answer to black's mate in 7.} 21. Be3 Qxe3 22. h4 Qf4 23. Qh3 Bxf2+ 24. Kxf2 Re2+ 25. Kf1 Bg4+ 26. Qf3 Qxf3+ 27. Kg1 Qg2#) 18... Rxf6 19. cxd4 Bxd4+ 20. Kh1 Rxf1+ 21. Nxf1 Re1 22. Bd3 Bf5 23. Be2 Rxe2 24. Bh6 Be4 {White resigned.} 0-1