eclipse zones and 8 ball
Rewritten: December 13, 2002
THE STRATEGY OF EIGHT BALL
Playing Pool in the Park
When I take my dog to the park, he can go anywhere he wants. But he must play inside the park.
But my dog, Rover, has been squished down to the size and shape of a cue ball. And the park has shrunk down to the size of a bar pool table. Now, poor Rover can only roll in a straight line. But he is free to roll anywhere in the 24 square foot park.
Then his master brings in 15 more ball-dogs. (Yup, that’s the rack.) Together, all the other ball-dogs may only take up one square foot of park space, but Rover is not happy. That square foot used to be his and now he’s down to 23 square feet to play in.
And if things weren’t bad enough, his master lets all the dogs loose at once. (The break.) When all the other ball-dogs finally stop running around, Rover discovers they’re blocking a lot of the straight lines he’d like to play in. Most of Rover’s 23 square feet of play space is blocked now. So Rover sits here and he sits there; and he notices his available play space keeps changing. The other ball-dogs don’t move or change size. What’s happened to Rover’s play space?
Let’s see if we can help Rover figure out what happened.
We’ve told Rover to “stay”. And now we’ve transformed the poor dog into a flashlight and turned off all the other lights. Rover’s powerful light beam hits a nearby ball. We can see the shadow it casts. This shadow gets larger as Rover comes closer. When Rover finally touches the other ball, the shadow has grown enormous. It covers the entire width of the park!
Rover has finally discovered where all his play space has gone. Have you?
Like a beam of light, Rover can only move in a straight line. But his light beam gets blocked by the other balls. They block the normal, free movement of the cue ball. The shadows show where Rover can’t go. Rover calls the shadows, “eclipse zones”.
Now Rover understands. When the other balls are in the park, their eclipse zones gobble up a lot of the “public” space. Rover’s public park has been changed into something more like a neighborhood. The 15 ball-dogs, with their eclipse zones, have carved out their own “private” yards. And now poor Rover must play in the street!
This new neighborhood is a strange and spooky place because the “yards” move! As Rover moved to sit here or there, the eclipse zone “yards” would follow, always staying opposite him. And their shapes would change as he moved closer or farther away.
He may not be crazy about the neighborhood, but Rover thinks of himself as a lucky dog, now. He realizes that he’s in charge. The other ball-dogs may be defensive about their “yards”, but Rover has offensive power. He can move. He can change the shape and size of their defensive eclipse zones simply by changing his location. By selecting the right spots on the table, he can weaken the opponent’s object ball defense during his master’s turn. And he can strengthen his master’s ball group defense when the table gets returned to the opponent. It’s all up to Rover.
We’ve all probably known the cue ball is a weapon of offense. Now we can see that the object balls are defending table space, trying to keep the cue ball out, playing a tough defense against his attempts at offense. They weaken his freedom of movement. They limit his ball choices. And they defend their table space like it was private property.
Rover’s a happy dog now. Even with 15 other ball-dogs in the park; he’s still top dog.
And that makes YOU the cue ball’s master, right?