Novotny

The Novotny theme is probably one of the oldest ideas in chess compositions.  The mechanism is due Antonin Novotny (1827-1871) and is related to the Grimshaw interference.  The idea is the following: if a rook and bishop's lines cross each other, at a square called the critical square, then if white places a piece on the intersection of the two lines it will block both lines so that white can exploit this.  The key usually makes a double threat and the captures of the key piece force the individual threats (not always though!).  Since the Novotny's have been around for close to two centuries, problems that have only a Novotny mechanism are generally not very interesting.  However, when combined with other ideas the Novotny has given rise to a large number of excellent problems.

Hoeg, Niels
Deutsche Schachblatter 1927

#2

3 + 4

 
Here is the simplest example of the theme I could find.  The square c7 is the critical square that blocks the bB and bR's line.  The key 1.Sc7 blocks both of these lines and makes the double threat 2.Qd8/Qg7.  The capture of the wS by the bB blocks the bR's line allowing only 2.Qg7 while the capture by the bR allows only 2.Qd8.  A textbook example.

Tura, Waldemar
Europe Echecs 1962

#2

10 + 11

Here is a fine example of Novotny tries forming a white Grimshaw.  The solver will notice the set Grimshaw on b4: 1...Rb4 2.Qe1, 1...Bb4 2.Qxd4.  So we can try 1.Bb4? threatening 2.Qe1/Qxd4.  However, 1...Be6 defeats the threats by closing the wBc8 guard on f5.  White cannot play the set mate 2.Rb5 because the key piece is blocking the way.  Likewise, 1.Rb4 fails to 1...Re6 because now the wR has blocked the wBa3 to d6.  Finally, the key is 1.Be6 this time a Novotny on e6!  Captures of the key piece separate the threats.  Meanwhile Black can defeat both threats by playing to b4 but these create a black grimshaw and allow the other threats.  To recap: we have two Novotny tries creating a white Grimshaw and a different Novotny key which is defeated by black Grimshaw moves allowing the original threats.  

  

Bwee, Touw Hian
Deutsche Schachblätter 1965

#2

11 + 11

Now a try problem from the great THB.  The critical square is g4 and six (!) different pieces have access to it.  Each Novotny try is uniquely defeated:

     1.Rcg4? axb4!
     1.Rgg4? Sg5!
     1.Bg4? Sxe5!
     1.Seg4? Bc5!
     1.Sfg4? Bd4!

The key 1.g4! .
​

Prcic, Mike
The Problemist Supplement 1998

#2

5 + 4

Here is a neat variant of the Novotny in a light setting.  The wSc1 is ready to mate on d3 and e2 as soon as the bR. The key moves precisely to the critical square 1.Be4!  I call this problem a delayed Novotny, because the key appears to make the double threat 2.Sd3/Se2 since it closes the bR and bB lines.  However it does not make these threats because it also grants a flight square in its sacrificial move.  Instead it makes a single threat 2.Qh4.  Captures of the key piece lead to the Novotny mates 1...Rxe4 2.Sd3, 1...Bxe4 2.Se2.  Nice by-play: 1...Bg5 2.Qf3, 1...Kxe4 2.Qf3, 1...Bf5 2.Qxf5.  

Dombrovskis, Alfred
The Problemist 1959

#2

7 + 6

Here is something kind of fun.  Notice the wRc2 is already acting as a Novotny piece.  The Novotny key 1.Bg5 makes a quadruple threat: 2.Qf7/Qb3/Qxd5/Rf4.  Each of the captures on c2 and g5 individually force the threats:

      1.Rxc2 2.Qf7
      1.Bxc2 2.Rf4
      1.Rxg5 2.Qb3
      1.Bxg5 2.Qxd5

​Perfect execution from the great Russian composer.
​

Sydenham, Colin
Norsk Sjakkblad 1980

#2

8 + 4

 
And now for something fantastic.  With only 12 pieces the composer pulls off a perfect disappearing Novotny.  The key appears to be a simple Novotny 1.Be5 threatening 2.Qd6/Qe6.  We've seen it all before the capture on e5 by the rook should lead to Qd6 and capture by the bishop should lead to Qe6.  Wrong!  1...Rxe5 removes the guard of d6 hence does not permit 2.Qe6 but does self block and allows 2.Rd8.  1...Bxe5 removes guard of d4 and again self blocks allowing 2.Be6.  

Shire, David
Die Schwalbe 1997

#2

9 + 9

You can always count on something good from this composer.  The critical square is d4.  The problem features a Novotny try and key.  Let's try 1.d4? which looks like it makes two threats 2.Rf6/Rf2, however because it unguards e4 it only makes the single threat of 2.Rf6.  The self-blocking defense 1...e4 allows 2.Rf2.  However this try is defeated by 1...Be7!  The correct key is 1.Bd4 which has a similar effect of appearing to threaten both 2.Rf6/Rf2, however because the bishop unguards g3 there is only one threat: 2.Rf2.  Again the self blocking defense 1...hxg3 allow for the suppressed threat 2.Rf6.  This type of pattern is known as the pseudo Le-Grand and this particular form with the avoided threats is known as a Sushkov theme.  The composer is a known expert of the Sushkov theme.

Sydenham, Colin
The Problemist 1992

#2

11 + 8

We could probably devote a whole blog post to the Novotny ideas of this composer. This is a really interesting that idea you could call a Novotny switch.  Notice that there is a set Grimshaw interference on f6 1...Bf6 2.Rb6 1...Rf6 2.Rf4 (shut-off).  The try f6 exploits this but is defeated by 1...Qxc5.  Instead the key 1.Sf6 looks like it should threaten those two mates but it does not.  Why?  Because it open up the lines of the other bR and bB which guard those threats.  It also opens up two white lines and hence has two new Novotny threats 2.Rc4 (since the wBg8 guards this square) and 2.Bb6 since the wRd4 now guards d6.  However, the bBg2 and bRd8 can now close both of these lines by playing to d5 but this only brings back 2.Rb6 and 2.Rf4.   This also has an interesting wrinkle in that the bQ, which possesses the power of a rook and bishop can capture the Novotny piece, but this leads to 2.Qc1.  

Sydenham, Colin
The Problemist 1984

#2

7 + 8

Here is probably one of my favorite Novotny ideas of all time: the masked Novotny.  Notice that the wBe7 and wRg6 could mate except that they are doubly controlled, once from the rear and once indirectly.  The key 1.e4! moves to the critical square of the bRe8 and bBh7 and threatens 2.Rd1.  Black can defend with 1...Qb6 pinning the wR but this removes the rear guard on the wBe7 and the key pawn blocks the bRe8's path so that 2.Bg5 mates.  Likewise 1...Rxg5 also defends by removing guard on d1 but also gives up its position on the wRg6.  The wP again blocks the bBh7 allowing 2.Rc6 to mate.  Nice by-play 1...dxe4 2.Rc4. 

Moen, Kabe
Original

#2

7 + 7

Here is something for your solving pleasure.  Given the fact that it is a Novotny you will probably figure it out quickly.  One of the virtues it possesses is that it makes a single threat and the Novotny mates only work after the captures.  Have fun.