Nimzowitsch explained this as a protected piece on the opponent’s side of the board that cannot be attacked by a pawn.
Karpov, Anatoly vs Kasparov, Garry 1-0 World Championship 35th-KK5 Rnd:17
Lyon/New York 1990.12.05
ECHESSPEDIA
Quotes of the Day
You can’t look too annoyed or they’ll look for the mistake you’ve made. A lot of the time it’s about looking for these opportunities and if you give them a clue, the good players will find it.
Magnus Carlsen 2016
it would have been a debacle if Karjakin had become the 17th World Champion.
Garry Kasparov 2016
I think I like chess. That’s the main reason that I’m able to play at a reasonably high level – that I really love chess. Always have and always will (smiles). It’s the best game in the world!
Nigel Short 2016
Unfortunately this gentlemanlike behaviour among chessplayers is out of fashion. It’s my principle that you should respect your opponent as much as you respect yourself.
Lajos Portisch 1990
The winner of the game is the player who makes the next-to-last mistake.
Savielly Tartakower