Voluntary blot in contact bearoff = "BARE-OFF"
Pivotal position

A position from Jerry Grandell vs Chris Ternel 21 pt. Semi Final Istanbul January 1999
Brown Jerry Grandell, White Chris Ternel

The final was Grandell vs Leonid Riskin with a fine good humored commentary by Nack

I coined the term for myself back on 22 September 2002 celebrating a new knowledge gained with Snowie.
The method "bare-off" was similar to the "off-guard" of Muhammad Ali (Cassius Clay) in his best boxing years. The positions and commentary are Snowie 3 3ply estimates from 2002. I Posted my observations in a PDF file but few may have read it because the PDF used local fonts as I noticed in 2010 :(
If you research a position where two concepts (here safe vs bold play) struggle for dominance, you need to find the PIVOTAL POSITION. If you remember that PIVOTAL, any time you encounter a similar position you can decide which concept prevails by the nature of the additional features of the new positions of THIS TYPE.
(Brown) vs. (White)
21 point Match

Match to 21. Score Brown-White: 7-5




 
Pip: 50
Game 1
21 point match

Brown-White:
Score 7-5
Pip: 35
 

# Ply Move Equity
  1 3 6/off 44.83%
    0.0%   0.0%  47.6%    52.4%   0.0%   0.0%
    Full 3-ply, 100%.
  2 3 5/off 3/2 44.00% (-0.84%)
    0.0%   0.0%  45.4%    54.6%   0.0%   0.0%
    Full 3-ply, 100%.
  3 2 5/off 2/1 43.82% (-1.01%)
    0.0%   0.0%  45.0%    55.0%   0.0%   0.0%

Comment
This is the position where Chris Ternel rolled 51 and made a blunder 6/1 6/5.
This is a technical position and it is an interesting study.
Bearing a checker off is better than not. So 5/0,5/4 is better than 6/1 6/5. With 7 Black checkers off White is just a small favorite before the roll. Now that White rolls medium (high
and low) and is able to pick only one checker, White is already the underdog, because he is forced to open
his board. If Black enters, he will be a huge favorite. White would prefer to be hit in such a case in order to
be able to meet Black's inside blot or the back checker.
What is the better point to leave slotted, the 5 or the 6? The 6, because it maims a higher number - 6 and
because it is more flexible and economic to play next turn.

Before deciding to bare-off or not, white needs to estimate how desperate his position is. The less desperate, the less he is inclined to bare-off.


(Brown) vs. (White)
21 point Match

Match to 21. Score Brown-White: 7-5




 
Pip: 50
Game 1
21 point match

Brown-White:
Score 7-5
Pip: 32
 

# Ply Move Equity
  1 3 5/off 5/4 43.50%
    0.0%   0.0%  44.1%    55.9%   0.0%   0.0%
    Full 3-ply, 100%.
  2 3 6/off 43.22% (-0.28%)
    0.0%   0.0%  43.4%    56.6%   0.0%   0.0%
    Full 3-ply, 100%.
  3 2 5/off 2/1 42.59% (-0.90%)
    0.0%   0.0%  41.7%    58.3%   0.0%   0.0%

Comment
.If Black has 7 checkers off and no blot, the safe play is best, but by a "doubtful margin". This is the real PIVOTAL POSITION. No wonder In January 2010 Stick Rice's XG rollout showed it to be a bare-off.


(Brown) vs. (White)
21 point Match

Match to 21. Score Brown-White: 7-5




 
Pip: 50
Game 1
21 point match

Brown-White:
Score 7-5
Pip: 31
 

# Ply Move Equity
  1 3 6/off 40.65%
    0.0%   0.0%  36.6%    63.4%   0.0%   0.0%
    Full 3-ply, 100%.
  2 3 5/off 5/4 40.27% (-0.38%)
    0.0%   0.0%  35.6%    64.4%   0.0%   0.0%
    Full 3-ply, 100%.
  3 2 5/off 3/2 39.77% (-0.88%)
    0.0%   0.0%  34.2%    65.8%   0.0%   0.0%

Comment
.Take one more Black checker off (8 black checkers off).
On a 51 roll Black would rather leave a challenge blot again 6/0 even without an inner Black blot.
0.024 better than 5off, 5/4

(Brown) vs. (White)
21 point Match

Match to 21. Score Brown-White: 7-5




 
Pip: 50
Game 1
21 point match

Brown-White:
Score 7-5
Pip: 30
 

# Ply Move Equity
  1 3 6/off 36.95%
    0.0%   0.0%  26.8%    73.2%   0.0%   0.0%
    Full 3-ply, 100%.
  2 3 5/off 5/4 36.36% (-0.59%)
    0.0%   0.0%  25.2%    74.8%   0.0%   0.0%
    Full 3-ply, 100%.
  3 2 5/off 3/2 36.09% (-0.86%)
    0.0%   0.0%  24.5%    75.5%   0.0%   0.0%

Comment
With 9 black checkers off the non-lift is 0.038 better. Playing "safe" is nearly a blunder.

(Brown) vs. (White)
21 point Match

Match to 21. Score Brown-White: 7-5




 
Pip: 50
Game 1
21 point match

Brown-White:
Score 7-5
Pip: 36
 

# Ply Move Equity
  1 3 6/off 49.76%
    0.0%   0.0%  58.1%    41.9%   0.0%   0.0%
    Full 3-ply, 100%.
  2 2 5/off 2/1 48.50% (-1.26%)
    0.0%   0.0%  56.6%    43.4%   0.0%   0.0%
  3 2 5/off 3/2 48.44% (-1.31%)
    0.0%   0.0%  56.6%    43.4%   0.0%   0.0%

Comment
Let us move in the opposite direction
With 6 Black checkers off ( one less compared to the original position AND THE SAME BLOT, it is the same big blunder (-0.110). not to leave the blot with 6 black off.

(Brown) vs. (White)
21 point Match

Match to 21. Score Brown-White: 7-5




 
Pip: 50
Game 1
21 point match

Brown-White:
Score 7-5
Pip: 33
 

# Ply Move Equity
  1 2 5/off 5/4 50.15%
    0.0%   0.0%  59.2%    40.8%   0.0%   0.0%
  2 2 6/off 48.40% (-1.75%)
    0.0%   0.0%  54.0%    46.0%   0.0%   0.0%
  3 2 6/1 6/5 46.86% (-3.29%)
    0.0%   0.0%  53.0%    47.0%   0.0%   0.0%

Comment
The other side of the coin
If Black has only one less checker off and no Black blot (6 checkers off), White would rather play safe.
White has certainly more chances
to roll higher than to meet a Black checker. This means that the position is a benchmark.

(Brown) vs. (White)
21 point Match

Match to 21. Score Brown-White: 7-5




 
Pip: 50
Game 1
21 point match

Brown-White:
Score 7-5
Pip: 34
 

# Ply Move Equity
  1 1 5/off 5/4 53.03%
    0.0%   0.0%  69.3%    30.7%   0.0%   0.0%
  2 1 6/1 6/5 50.83% (-2.20%)
    0.0%   0.0%  63.5%    36.5%   0.2%   0.0%
  3 1 6/off 50.40% (-2.63%)
    0.0%   0.0%  62.4%    37.6%   0.0%   0.0%

Comment
The other side of the coin 2.
If Black has only one less checker off (5 checkers off, no blot), White would rather play safe again. He is the
favorite and even if Black enters Black cannot gain a decisive advantage. White has certainly more chances
to roll higher than to meet a Black checker. This means that the initial position is a benchmark.
With only 6 Black checkers off, even an inner blot would not induce White to leave a voluntary blot.
With as much as 9 Black checkers off, White would rather blot even without a Black inner blot.
Aftermath

In the meantime more systematic concept was developed, showing that the desision to bare-off or not depends on 1. difference of checkers off, 2. state of opponent's board (number of points, blot). 3. Ownership (or not) of a "speedboard". A speedboard is a board with surpluses on the higher points so one bares off without opening new entry points for the opponent. The opposite of speedboard is the stripped board with supluses on the ace point. A speedboard improves position and dissuades from bare-off.

In 2006 Francois Tardieu wrote this.
and this

In January 2010 Same theme in the BgOnline forum.

I saw a similar discussion on Robertie's BB in 2plus2 in December 2009

Svilo 2010.01