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How do you define a containment game?

Posted By: Matt Cohn-Geier
Date: Friday, 15 September 2023, at 5:34 a.m.

In Response To: How do you define a containment game? (Frank Berger)

1. Contact position.
2. <15 checkers in the home board.
3. <6 prime.
4. No contact (or limited contact) between White's home board and Blue's back checkers.

For example, the following positions are containment games:

		White is Player 2 score: 0 pip: 69 Unlimited Game Jacoby Beaver pip: 103 score: 0 Blue is Player 1
XGID=-aDBa-E-----AB-------Acee-:0:0:1:00:0:0:3:0:10
Blue on roll, cube action?

eXtreme Gammon Version: 2.19.211.pre-release

		White is Player 2 score: 0 pip: 45 Unlimited Game Jacoby Beaver pip: 188 score: 0 Blue is Player 1
XGID=------CaB----DB---BB--dee-:0:0:1:00:0:0:3:0:10
Blue on roll, cube action?

eXtreme Gammon Version: 2.19.211.pre-release

Whereas this is not a containment game:

		White is Player 2 score: 0 pip: 70 Unlimited Game Jacoby Beaver pip: 101 score: 0 Blue is Player 1
XGID=-aBBCCC------------bbbdBd-:0:0:1:00:0:0:3:0:10
Blue on roll, cube action?

eXtreme Gammon Version: 2.19.211.pre-release

Not obvious how far back White's back checkers should be, but I guess at some point I would call it more of a "holding game" than a "containment game", although a containment game is in some sense just a result of a holding game.

This is a containment game:

		White is Player 2 score: 0 pip: 60 Unlimited Game Jacoby Beaver pip: 188 score: 0 Blue is Player 1
XGID=------CbB----DB---BB--cee-:0:0:1:00:0:0:3:0:10
Blue on roll, cube action?

eXtreme Gammon Version: 2.19.211.pre-release

And I'd call this a containment game:

		White is Player 2 score: 0 pip: 50 Unlimited Game Jacoby Beaver pip: 188 score: 0 Blue is Player 1
XGID=------C-B---bDB---BB--cee-:0:0:1:00:0:0:3:0:10
Blue on roll, cube action?

eXtreme Gammon Version: 2.19.211.pre-release

In these 2 positions, Blue is almost always hitting a shot and attempting to contain it unless White runs home with a joker, which can happen whether White has a point or a single checker back.

But this is a holding game:

		White is Player 2 score: 0 pip: 60 Unlimited Game Jacoby Beaver pip: 188 score: 0 Blue is Player 1
XGID=------C-B----DB--bBBdcbbb-:0:0:1:00:0:0:3:0:10
Blue on roll, cube action?

eXtreme Gammon Version: 2.19.211.pre-release

Now White is almost home and Blue rarely hits a shot.

An important distinction might be containment with dead (or semi-dead) checkers vs. containment without dead checkers.

Also not clear at which point it switches to the other way, e.g., I'd call this a bear-in or a holding game, even though Blue is behind in the race and is in some sense containing White's back checkers:

		White is Player 2 score: 0 pip: 80 Unlimited Game Jacoby Beaver pip: 95 score: 0 Blue is Player 1
XGID=--BBCbC-B----C------ccbbc-:0:0:1:00:0:0:3:0:10
Blue on roll, cube action?

eXtreme Gammon Version: 2.19.211.pre-release

Messages In This Thread

• How do you define a containment game?
  Frank Berger -- Thursday, 14 September 2023, at 7:56 p.m.
  • How do you define a containment game?
    Timothy Chow -- Friday, 15 September 2023, at 3:12 a.m.
  • How do you define a containment game?
    Matt Cohn-Geier -- Friday, 15 September 2023, at 5:34 a.m.
    • How do you define a containment game?
      svilo -- Friday, 15 September 2023, at 12:34 p.m.
  • How do you define a containment game?
    Frank Berger -- Friday, 15 September 2023, at 5:20 p.m.
  • How do you define a containment game?
    Frank Berger -- Tuesday, 26 September 2023, at 5:59 p.m.