Abdel Irada: <<•>The War of the Plumbers?<•>>
After Stefansson planted his knight on h6, Norqvist vowed to shrink it until he could drown it in his bathtub. In that case, retorted Stefansson, I'll have to throw the kitchen sink at you.
With the key move,
<<•> 21. Qc4 >,
White takes advantage of Black's own forward (not to say froward) knight, which doesn't have time to retreat.
If it tries, there might follow (a) 21. ...Nb5? 22. Nxf7 and White wins in view of 22. ...Rxf7 (otherwise the combined threats against king and queen are too much) 23. Qxf7†, Kh8 24. Bh6, Bf6 25. Bf8, Be6 26. Bxe6, Qxf8 27. Nxa8 .
Black cannot simply permit his rook to be picked off, but allowing 22. Nxf7 is also not an option, so he must try one of the following.
< (1) 21. ...Be6?
22. Qxc3, Bxb3
23. Qxb3, Nxa5
24. Rxa5, Rb6
25. Rxa6 >
Black has saved the rook and the kingside, but is two knights down and has no obvious prospects for making up the deficit.
He must therefore make a more direct attempt to undermine the knight in quest of counterplay.
<<•> (2) 21. ...Nxa5
22. Rxa5, Qxb6
23. Nxf7! ... >
This sets a pretty challenge: Take my rook and see what happens!
< (2.1) 23. ...Qxa5?
24. Bh6†, Kg8
25. Ng5†, Kh8 >
Black has various interpositions, but they don't help.
< 26. Qg8†!, Rxg8
27. Nf7# >
And lo! White has found a version of Philidor's notorious Legacy: the smothered mate.
Note well that there is no hope in (b) 23. ...Rxf7? 24. Qxf7†, Kh8 25. Qg8#, so Black has only one sensible option.
<<•> (2.2) 23. ...Be6
24. Qxe6, Qxe6 >
Black still can't survive either (c) 24. ...Qxa5? 25. Bh6†, when White mates as in line (2.1) or (d) 24. ...Rxf7? 25. Qxf7†, Kh8 26. Bh6, Qf6 27. Rxa6!, Qxf7 28. Rxa8† .
<<•> 25. Bxe6, Rxf7
26. Bxf7, Kxf7
27. Bb2, Nb5
28. Bxe5 >
In this variation, Black's best defense, White emerges the exchange ahead. Victory will not be immediate, but the result is not in doubt.
When two men vie to plumb so deep a position, fortune smiles upon him who plumbs deeper, and his opponent's best laid plans are sure to go down the drain.