J M Hanham vs Steinitz, 1894 (31....?)

Black to play and win.

Material: Too fast to count. The White Kh1 is stalemated. The usual Monday Q sac, with a variant of Philidor's legacy, finishes White off..

Candidates (31...): Qg1+

How many pieces does it take to force mate? You might think that this is one of those "how long is a piece of string" questions. You can mate with just one piece:

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Or you can sometimes throw your entire army at your opponent to mate with your last piece or pieces, as in Morphy's opera game.

But, on average, how many pieces does it take to mate a king in the middlegame? I haven't done any scientific analysis of this, but I think the answer would be around three.

Incidentally, I have a theory that three is something of a magic hidden number in chess, a sort of chess pi. But that is a story for another time. Today we need to talk about Star Trek's infamous red shirts, and how they help us to give mate in the middlegame.

The makers of Star Trek had a problem. The show is supposed to be about a starship with a crew of several hundreds, but they had to make it with a regular cast of less than 10 actors. And nearly all of those were bridge officers, because most of the action takes place on the bridge.

So how exactly do you shoot a scene away from the bridge, say when they need to beam down to a planet to meet an alien race? The answer, somewhat unconvincingly, was to take most of the senior staff down to the planet, leaving only Scotty or Chekov in charge of the Enterprise. And that was dangerous, as Scotty's main role in life was to increase the tension at key moments by saying in his Canadian/ Scottish accent: "the engines cannae take it". Not exactly what you would call command material. If all of the away team were killed, the USS Enterprise would spend the rest of its five year mission boldly making repairs.

And that's also where the red shirts come in. If the away team is made up almost entirely of senior officers, who gets killed when the plot calls for a death ray or ravenous beast to reduce the crew complement by one? You can't kill off your main characters (not until the movies, and then they had an annoying habit of coming back to life). So you need to bring along an unnamed crewman, nearly always in a red shirt, to take one for the team. Then Bones could wave a glowing lipstick over him and say "he's dead, Jim" or "I'm a doctor, not a miracle worker."

Most middlegame mating combinations seem to fall into a similar pattern. We usually need two main pieces to deliver the mate - in today's puzzle a knight and bishop - and a third red-shirted piece (today, that's the queen) to give up its life in order to demolish or distract the defending pieces.

And that also helps us to build up our mating attacks. I am not saying that you can't mate with just one piece or two. But it is certainly much harder to break down a half-decent defence. In most instances, you need to train at least three pieces on the squares around the enemy king. For long range pieces (bishops, queen, rooks) that means open lines, but the knight needs to be launched up the board, preferably to find an outpost.

If you want to be a better player and launch mating attacks, remember the rule of three and always bring along a red shirt or two...

White is counting on the fact that once black moves the queen, white will have a mating combination starting with 32 Rxf8+.

However, there is one square that black can move the queen to that foils that plan:

31...Qg1+ 32 Rxg1

Forced.

32...Nf2#

<31....?>

Target: 0:40;000
Taken: 0:08;479

Material: Black up, +

Candidates: <[Qg1†]>

-ML-
I think White is a piece down here because he gave it away, in the assumption Rf1 would win him a Rook back. Well, not really.

And that points to a typical mating force being at least three pieces - one to be sacrificed and two to construct the mating net. Or, back in the language of star trek, a typical away mission would involve Kirk, Spock plus the guy in the red shirt.

I find that lower-graded players hate to sacrifice pieces, even if it is a pseudo-sacrifice which quickly results in a mate. And they also think that they can whip up an attack with just one or two pieces.

So my little Star Trek story was intended as a little chess parable. Don't be afraid to sacrifice a piece if mate follows soon after. And always try to bring along at least three pieces into an attack so that you have got one to sacrifice. All wrapped up in a bit of whimsy, hopefully making it easier to remember.