notyetagm: Black to play: 20 ... ?
 click for larger viewHere Botvinnik (Black) snatches a pawn in broad daylight with 20 ... ♘f5xh4!, using the tactic <DISCOVERED DEFLECTION>. Position after 20 ... ♘f5xh4!
 click for larger view<DISCOVERED DEFLECTION>: Use the masking piece (Black f5-knight) to exploit the <LOOSENESS> (White f4-knight) created by the unmasking of the rear line piece (Black f6-queen) by taking what the newly <OVERWORKED> defender (White g3-pawn) no longer defends (White h4-pawn, 20 ... ♘f5xh4!). Botvinnik saw in the first position that without his Black f5-knight <BLOCKING> the f-file from the Black f6-queen to the White f4-knight, that the White f4-knight would be <LOOSE>, with two Black attackers (Black f6-queen and h6-bishop) versus two White defenders (White d2-queen and g3-pawn). Since there would be an equal number of Black attackers (2) as White defenders (2), these two White defenders would be automatically <OVERWORKED>, <<<meaning that some squares would only -appear- to be <DEFENDED> (--)>>>. So, since the White g3-pawn would have to <DEFEND> the White f4-knight if the Black f5-knight were not <BLOCKING> the f-file, the White g3-pawn could not then -also- <DEFEND> the h4-pawn, hence 20 ... ♘f5xh4!. <DISCOVERED ATTACKS> that make things <LOOSE> are dangerous, dangerous, dangerous! |