9. Ng5 weakened things, and there are doubts r.e. the followup. E D'Andre vs De Vere, 1867  (A02) Bird's Opening, 14 moves, 0-1 Unguarding the back rank J S Stanley vs C G Heydon, 1872  (C42) Petrov Defense, 28 moves, 0-1 40. ... Re1? Bird vs W Pollock, 1889   (B01) Scandinavian, 56 moves, 1-0 Bishop exchange -- very bad idea M Porges vs Winawer, 1892  (B06) Robatsch, 22 moves, 0-1 Resigned immediately after 44.c4?? Lasker vs F R Gittins, 1897  (C45) Scotch Game, 44 moves, 0-1 Ceci n'est pas un Amos Burn. Marshall vs Burn, 1900   (D55) Queen's Gambit Declined, 18 moves, 1-0 With the K-side weakened, the Pawn hunt loses to a King hunt. L Karpinski vs Marshall, 1901  (C43) Petrov, Modern Attack, 27 moves, 0-1 "Take my wife--Please!" K B Finn vs W C Palmer, 1903  (D08) Queen's Gambit Declined, Albin Counter Gambit, 10 moves, 0-1 When setting up a mate net, still mind your opponent's threats! Duras vs E Post, 1904  (C77) Ruy Lopez, 23 moves, 1-0 Queened the Pawn--and then threw it away. F Duz-Khotimirsky vs Alapin, 1908  (D02) Queen's Pawn Game, 78 moves, 1-0 Hanging a piece as recapturing leads to back-rank mate Tarrasch vs Lasker, 1908  (C49) Four Knights, 26 moves, 0-1 Too greedy in the opening J Krejcik vs Baumgartner, 1914  (C40) King's Knight Opening, 7 moves, 1-0 Blundered away the Knight J Mieses vs Euwe, 1921  (C45) Scotch Game, 12 moves, 1-0 Poaching crows--a terrible mistake H Walkerling vs Hanssen, 1928  (B40) Sicilian, 10 moves, 1-0 Opening errors walk the White K into Black's masterful net. Glucksberg vs Najdorf, 1929  (A85) Dutch, with c4 & Nc3, 22 moves, 0-1 5.Nc3 did nothing to parry My Little Checkmate. M Warren vs Jan Selman, 1930  (B20) Sicilian, 5 moves, 0-1 Watch out for peer pressure! A Ebralidze vs Ragozin, 1937  (E60) King's Indian Defense, 45 moves, 0-1 The P isn't truly pinned if capturing the R is a blunder. V G Kirillov vs Blankstein, 1938  (C04) French, Tarrasch, Guimard Main line, 10 moves, 0-1 exd3?? == falling for one fast-acting poisoned Pawn. H Haberditz vs Hysek, 1938  (A04) Reti Opening, 8 moves, 1-0 Too many fronts at once. M Stark vs Shainswit, 1943  (D35) Queen's Gambit Declined, 33 moves, 0-1 Black's QBP was a golden dart frog for White's Q! W Adams vs G Kramer, 1946  (B12) Caro-Kann Defense, 9 moves, 0-1 Petrosian has Bronstein skunked--and blunders away his Q Petrosian vs Bronstein, 1956  (E66) King's Indian, Fianchetto, Yugoslav Panno, 36 moves, 0-1 Missed chance to refute sac, then missed chance to draw. A G Murphy vs C Witte, 1957  (B20) Sicilian, 23 moves, 0-1 19. Kh1 didn't work, then a later Queen trade lost fast. M Tamburini vs E Paoli, 1957  (A44) Old Benoni Defense, 30 moves, 0-1 Opening enemy lines for a mate in two Sliwa vs Malich, 1957  (A43) Old Benoni, 45 moves, 0-1 Naturally, the first Chess computer was a total patzer. Bronstein vs M20, 1963  (C34) King's Gambit Accepted, 23 moves, 1-0 Knight-snatching enables checkmate net. A Matanovic vs J H Donner, 1965  (C70) Ruy Lopez, 21 moves, 0-1 Blue-bearded Pawn-snatching D Walker vs Almeida, 1965  (C19) French, Winawer, Advance, 11 moves, 1-0 No time to prepare a fianchetto! P Pantelidakis vs F Rhine, 1974  (A02) Bird's Opening, 6 moves, 0-1 Wrong stable for that horse! A Seppelt vs Leganki, 1950  (C07) French, Tarrasch, 6 moves, 0-1 Pawn-snatching into a two-pin combination. Robatsch vs Jansa, 1974  (A10) English, 14 moves, 1-0 Forty minutes of thought for THAT sort of blunder!? Gligoric vs Andersson, 1974  (E44) Nimzo-Indian, Fischer Variation, 5.Ne2, 49 moves, 1-0 4. d4 parried mate aspect but not the rest of the threat. A Riemslag vs P Cameron, 1978  (A02) Bird's Opening, 9 moves, 0-1 In the opening, watch out for threats to King Bishop 2! J Henningsen vs R Borik, 1979  (A00) Uncommon Opening, 7 moves, 1-0 Enabled a disastrous fork with check on move 3 Z Djordjevic vs M Kovacevic, 1984  (A45) Queen's Pawn Game, 3 moves, 0-1 A fork of King and Rook that did nada to address White's attack G Minchev vs B Ganchev, 1986  (B02) Alekhine's Defense, 13 moves, 1-0 11. Na3 did nothing to stop the checkmate. B Wall vs S Millimaci, 1988  (B22) Sicilian, Alapin, 11 moves, 0-1 Yes the Queen was left en prise/Yes Black right away did seize R Suess vs O Zenker, 1989  (A80) Dutch, 7 moves, 0-1 This was an easily-won K+P+P vs. K endgame, right? Dreev vs R Wessman, 1990  (D45) Queen's Gambit Declined Semi-Slav, 77 moves, 1/2-1/2 What sort of opening play is THAT!? M Mas vs R Guerrero, 1991  (C00) French Defense, 12 moves, 1-0 That horse left Her Majesty badly overworked. R Gonzalez vs Tal, 1992  (B32) Sicilian, 26 moves, 0-1 Uh, that Bishop was guarding the mate square. Karpov vs Bareev, 1994  (C07) French, Tarrasch, 36 moves, 1-0 For Pete's sake, don't castle onto a pawnless side! Ivanchuk vs Topalov, 1996  (B81) Sicilian, Scheveningen, Keres Attack, 23 moves, 0-1 Leaving the Rook en prise Piket vs Anand, 1998  (D86) Grunfeld, Exchange, 60 moves, 1-0 Hangs a Bishop for a Pawn Nisipeanu vs Ivanchuk, 1999  (C45) Scotch Game, 14 moves, 1-0 Leading with the Lady against a former World Champion? Boris Becker vs Kasparov, 2000  (C20) King's Pawn Game, 18 moves, 0-1 Castling into it U Capo Vidal vs E Gonzalez Chavez, 2001  (A54) Old Indian, Ukrainian Variation, 4.Nf3, 19 moves, 1-0 Bye-bye Queen. Bacrot vs M Vukic, 2004  (A46) Queen's Pawn Game, 29 moves, 1-0 Developing the Queen directly into the line of fire A Gautam vs J Worell, 2004  (C65) Ruy Lopez, Berlin Defense, 8 moves, 1-0 16. ... Ne3?? turns White's opening blunder into a sac. A Smirnov vs V Shepelev, 2005  (A00) Uncommon Opening, 22 moves, 1-0 Qf8?? Carlsen vs Bareev, 2005  (B12) Caro-Kann Defense, 46 moves, 0-1 Critical failures on both their spot checks. Wen Yang vs Z Almasi, 2007  (A20) English, 39 moves, 0-1 A N move in self-offense--B cannot now capture K-&-R-forking N. Shirov vs Kramnik, 2010  (E20) Nimzo-Indian, 38 moves, 1-0 4. Bg5?? and Black gets to kick White's K around. M Murara vs I Scott, 2012  (A51) Budapest Gambit, 13 moves, 0-1 131.Rc4?? 131.Ka2 with the perpetual would have been better. Giri vs Karjakin, 2014  (A35) English, Symmetrical, 131 moves, 0-1 Taking the Pawn did nothing to stop the fork. Sengupta vs S Narayanan, 2018  (A45) Queen's Pawn Game, 10 moves, 0-1 Blundered away a vital Bishop in the opening. Ameyalli Avila Fraire vs S Logothetis, 2019  (A07) King's Indian Attack, 11 moves, 1-0 Dodged the 77. a6? trap, but blundered a different way. Nepomniachtchi vs Anand, 2019  (A21) English, 77 moves, 0-1 150. ... Kc1 loses just four moves away from a 50-move draw V Kovalev vs D Gavrilescu, 2019  (C07) French, Tarrasch, 152 moves, 1-0 A fatal misclick about to cost the Queen Nepomniachtchi vs Carlsen, 2020  (C60) Ruy Lopez, 38 moves, 1-0 Marshall's 1940 P-pushing opening against Ragosin this wasn't. NN vs F Rhine, 2020  (A40) Queen's Pawn Game, 13 moves, 0-1 White missed 61.Ka4! winning. Giri vs Firouzja, 2021  (C11) French, 67 moves, 1/2-1/2 62 games