Chess Question: What is a good rule of thumb as to when you may and may not check a king?

[Quercus]

@davidmich

If your rook is between your king and your opponent’s queen then you can’t move that rook.

Just to be clear, this isn’t completely true. If your rook is between your king and your opponent’s queen, then you can’t move the rook out of the way (which would allow their queen to capture your king next turn).
But you can move the rook as long as the queen can’t capture the king next turn. If the queen is on a diagonal to the king (with the rook in between), then any move by the rook will expose the kind and would be illegal (because the rook can’t move diagonally). But if the queen is ‘square’ to the king (and the rook) on a row or file, then the rook can move anywhere along that line and still block the queen, or just capture the queen; and those are legal moves.

[glee]

@glee

Hi, I’m a retired chess coach. As a player, my highest ELO rating was 2390. (I’d be interested to hear how that compares to your teacher’s rating. )

Firstly this teacher is obviously drawing a conclusion from inadequate evidence (one chess club compared to millions of players world-wide.)
Using his simplistic standard - I taught chess for over 25 years at an English school. We won our National Schools Team Championship a couple of times and also many English Junior titles. Every single chess player went to university.

Secondly being a professional chess player these days is a full-time occupation. You need to use computers to study both your own games and to prepare against your rivals. You’ll need extensive knowledge of chess openings and the ability to concentrate continually for hours. You’ll have to cope with the pressure by yourself.
So these players need excellent analysing skill, a good memory and to be self-reliant.
They also tend to turn professional before going to University.

Now if you go back a few decades (where there were less full-time professionals, so players could do more academically), we can use the example of the English chess team ( who did incredibly well in Chess Olympiads, scoring three silver and two bronzes in eight successive competitions.)
Here’s the academic level and profession of those international players:

Tony Miles Maths, Sheffield; Chess Professional (d. 2001)
Ray Keene Modern Languages, Cambridge; Journalist, Author
Bill Hartston Maths, Cambridge; Journalist, Author
Michael Stean Maths, Cambridge; Tax Accountant
Jonathan Mestel Maths, Cambridge; University Professor
John Nunn Maths, Oxford (graduated at 18!); Author, Chess Professional
Jon Speelman Maths, Oxford; Author, Chess Professional
Nigel Short honorary degree, Bolton (GM title at 19); Chess Professional
William Watson Maths, Oxford; Tax Lawyer
Michael Adams (GM title at 17); Chess Professional

N.B. Cambridge and Oxford are the equivalent of Harvard and Yale.

@KarlGauss

Thank you for such a wonderful and thoughtful post!
(BTW, it seems maths are, in fact, overrepresented)
(speaking of maths, did you know Hugh O’D Alexander?)

You’re welcome!
I don’t recall Alexander playing at any chess events (I started competing in 1966.)
I have met all of the players that I posted above.

[glee]

@Really_Not_All_That_Bright

I beg to differ. The potential complexity of a chess match is far beyond that of any other board game. At least, beyond that of any other game that does not involve luck.

@The_Hamster_King

Chess is quite a bit simpler than Go.

@Little_Nemo

I disagree. I don’t see how chess is any more complex than a game like Hive, for example.

I agree that Go (like chess) is incredibly complicated.
I don’t know anything about Hive (it looks interesting though), but I doubt it can match chess for complexity.

Here’s some chess statistics:

• considering just the first 6 moves by each side involves nearly 10 million possible positions
• this position with just 6 pieces (White King g1, Rook g2, Bishop h1 v Black King e5 Knights d6, c5) is a win in 203 moves (by each side :eek:)
• this position with just 3 pieces (White Ke1, pawn e2 v Black Ke8) takes 22 moves to win (and there are lots of ways to go wrong…)

[Little_Nemo]

Chess can be a surprisingly complex game.