[Comment "auto-generated from http://www.jesseo.com/chesspublishing/pgn.php?pgndata=[Event%20%26quot;Paris%20sim%26quot;]%0A[Site%20%26quot;Paris%26quot;]%0A[Date%20%26quot;1858.??.??%26quot;]%0A[Round%20%26quot;?%26quot;]%0A[White%20%26quot;Morphy,%20Paul%26quot;]%0A[Black%20%26quot;Potier%26quot;]%0A[Result%20%26quot;1-0%26quot;]%0A[ECO%20%26quot;C42%26quot;]%0A[Annotator%20%26quot;Wilson,%20Glenn%26quot;]%0A[PlyCount%20%26quot;49%26quot;]%0A[EventDate%20%26quot;1858.??.??%26quot;]%0A[Source%20%26quot;ChessBase%26quot;]%0A[SourceDate%20%26quot;1998.11.10%26quot;]%0A%0A1.%20e4%20e5%202.%20Nf3%20Nf6%203.%20Bc4%20Nxe4%204.%20Nc3%20Nf6%205.%20Nxe5%20d5%206.%20Bb3%20Be7%207.%20d4%20c6%208.%0AO-O%20Nbd7%209.%20f4%20Nb6%20%26%23123;The%20d5%20pawn%20is%20the%20keystone%20of%20black%27s%20position.%26%23125;%2010.%20Qf3%0Ah5%2011.%20f5%20Qc7%2012.%20Bf4%20Bd6%2013.%20Rae1%20Kf8%2014.%20Qg3%20h4%2015.%20Ng6+%20Kg8%2016.%20Bxd6%20hxg3%0A17.%20Bxc7%20fxg6%2018.%20fxg6%20gxh2+%2019.%20Kh1%20Bg4%2020.%20Re7%20Nbd7%2021.%20Be5%20Kf8%2022.%20Rf7+%20Kg8%0A%26%23123;An%20important%20position.%20If%20the%20black%20pawn%20on%20d5%20disappeared,%0AMorphy%20could%20play%2023.%20R7xf6+%20and%20win%20(23...Be6,%2024.%20Bxe6%23).%20Also%20note%20that%20if%0Athe%20knight%20on%20f6%20disappeared,%20then%20Rxg7%20would%20be%20checkmate,%20so%20the%20f6%20knight%0Ais%20not%20really%20defending%20d5.%20How%20does%20Morphy%20make%20the%20d5%20pawn%20disappear?%26%23125;%2023.%0ANxd5%20$1%20%26%23123;A%20%26quot;Space%20Clearance%26quot;%20sacrifice%20that%20opens%20the%20a2-g8%20diagonal!%26%23125;%20cxd5%20(%0A23...%20Nxd5%2024.%20Rxg7%23)%20(23...%20Nxe5%2024.%20Ne7%23)%2024.%20Bxd5%20%26%23123;%0AExploiting%20the%20%26quot;Pin%26quot;%20of%20the%20f6%20knight.%26%23125;%20Nb6%20(24...%20Nxd5%2025.%20Rxg7%23)%2025.%20Bb3%20%26%23123;%0Aand%20the%20threat%20of%20R7xf6+%20is%20fatal.%26%23125;%201-0%0A"]
[Event "Paris sim"]
[Site "Paris"]
[Date "1858.??.??"]
[Round "?"]
[White "Morphy, Paul"]
[Black "Potier"]
[Result "1-0"]
[ECO "C42"]
[Annotator "Wilson, Glenn"]
[PlyCount "49"]
[EventDate "1858.??.??"]
[Source "ChessBase"]
[SourceDate "1998.11.10"]

1. e4 e5 2. Nf3 Nf6 3. Bc4 Nxe4 4. Nc3 Nf6 5. Nxe5 d5 6. Bb3 Be7 7. d4 c6 8.
O-O Nbd7 9. f4 Nb6 {The d5 pawn is the keystone of black's position.} 10. Qf3
h5 11. f5 Qc7 12. Bf4 Bd6 13. Rae1 Kf8 14. Qg3 h4 15. Ng6+ Kg8 16. Bxd6 hxg3
17. Bxc7 fxg6 18. fxg6 gxh2+ 19. Kh1 Bg4 20. Re7 Nbd7 21. Be5 Kf8 22. Rf7+ Kg8
{An important position. If the black pawn on d5 disappeared,
Morphy could play 23. R7xf6+ and win (23...Be6, 24. Bxe6#). Also note that if
the knight on f6 disappeared, then Rxg7 would be checkmate, so the f6 knight
is not really defending d5. How does Morphy make the d5 pawn disappear?} 23.
Nxd5 $1 {A "Space Clearance" sacrifice that opens the a2-g8 diagonal!} cxd5 (
23... Nxd5 24. Rxg7#) (23... Nxe5 24. Ne7#) 24. Bxd5 {
Exploiting the "Pin" of the f6 knight.} Nb6 (24... Nxd5 25. Rxg7#) 25. Bb3 {
and the threat of R7xf6+ is fatal.} 1-0