Other Tutorials

A queen can usually beat a bishop and a knight, but two fortresses do exist.  The first one, discovered by M. Karstedt in 1903, is generally believed to be the only one.

M. Karstedt's fortress

  1...Kg8 2. Qb3+ Kh7 3. Qd5 Bh8 =

Tom Morrell's fortress

This next one, discovered by Tom Morrell on July 3, 2005, isn't accepted by the chess community, yet.  However, the blockade on the squares e5, e6, e7, e8, f5, g5, h5 can't ever be penetrated by white's king, thus securing the draw (black must still play accurately, though).

  1...Kg6 2. Qg1+ Kf7 3. Kg4 Kg6 4. Qa7 Bc3 (4...Kh7?! 5. Qf7 Bb2 and 4...Kh6?! are still unassessed) 5. Qb6+ Bf6 6. Qc7 Bb2 7. Qd6+ Bf6 8. Qd3+ Kf7 9. Qh7 Ba1 10. Kg5 Bf6+ 11. Kg4 after white's unsuccessful penetration

Try it!

You can reach Tom at gambitguy@sbcglobal.net to try it against him.

Sorry for the mistake in the analysis.  11. Kg4? = is wrong.  11. Kh6! +- wins.  Black can still stop this from happening, though.  9. ... Ba1? allows white's king to penetrate.  9. ... Bf7 = holds on and prevents white's king from getting to h6.

Tom Morrell's actual analysis can be found at chess-studies.com.