Computer super-programs can blunder!. This is taken from Chessbase:
After six rounds of the Mercosur Cup in Argentina:
Lafuente,P (2435) - SHREDDER [The super-program, estimated close to 2800]
Mercosur Cup Vicente Lopez ARG (3), 16.07.2005
1.d4 Nf6 2.c4 e6 3.Nc3 Bb4 4.Qc2 d6 5.Nf3 Nbd7 6.Bd2 0-0 7.a3 Bxc3 8.Bxc3
Qe7 9.e3 b6 10.Be2 Bb7 11.0-0 Ne4 12.Nd2 Nxc3 13.Qxc3 c5 14.Bf3 Nf6 15.b4
Rac8 16.dxc5 dxc5 17.b5 Rcd8 18.Rad1 Rd6 19.Bxb7.
Lafuente has just captured a black bishop on b7, after which White must
recapture. But Shredder plays the unaccountable:
19...Rfd8??
The official bulletin says it was definitely not a mouse slip or any other
kind of operator error, but that Shredder thought for over three minutes,
initially analysing 19...Qxb7 to a depth of 20 ply but then switching to
the move it ultimately played. The evaluation showed a slight advantage
for Black. Only after the next move the value suddenly dropped to show a
decisive advantage for White. Afterwards the organisers tested the
critical position again with Shredder and diagnosed the problem as a 'one
in a million' error in the hash tables. (!!!). Lafuente won the game
without problems, but Shredder won the Tournament.
