Back game question

[calman]

Can you have too many men back? If so, about how many do you want (assuming
reasonable timing)

(P.S. Does Jf3.0 have a blind spot with regard to back games?)

[Fredrik Dahl]

calman wrote:
>
> Can you have too many men back? If so, about how many do you want (assuming
> reasonable timing)

In my oppinion this depends a lot on the position. Your assumption that
the timing is ok changes things quite a bit, as this is normally part of
the problem. As a general rule I tend to think that having 10 or 11 men
back is the worst, because then you'll be unable to make a prime
anywhere on the board for a LONG time. So even after a hit you'll have a
lot of work to bring the position home. If you have fewer back, you can
build a forward position quicker, while if you have close to all 15
back, you can build a prime in his outfield and roll it home.

>
> (P.S. Does Jf3.0 have a blind spot with regard to back games?)

I think it's pretty good with backgames :-) In extreme backgames, like
if you hold 4 anchors and have 12 checkers back, you may see
misevaluations of about 0.25 point cubeless. But it plays them quite ok,
in my oppinion. In ultimate backgames, with deep points and all 15 men
back, it will be weaker. When playing it will not normally allow this to
happen, but rather stop hitting after sending back 10 or 11...
It's far better with backgames than JF2.0.

--
- Fredrik Dahl

[Brian Sheppard]

calman <cal...@globalnet.co.uk> wrote in article
<01bc8d91$41645500$1e57...@Home.globalnet.co.uk>...

> Can you have too many men back? If so, about how many do you want
> (assuming reasonable timing)

Once you are committed to a back game (meaning that losing a
gammon is a foregone conclusion--unless you win!) the critical
issue is maintaining timing. Often that means having more
back men, but sometimes not. Let's take a few cases.

First, if the opponent has a full prime, or even 5-prime, then
any back men might not be able to escape. In that case the entire
burden of playing the dice falls to the forward forces, and these
may not be able to handle the load. This is a case where extra
men back can be harmful.

Another problematic case is where you have lots of men on the bar.
One of the best times to get a shot is as the opponent clears his
outside prime. There are two benefits to hitting such a shot.
First, the opponent hasn't borne off any men, so you can win with
the cube once you complete a prime (or even threaten to prime).
Second, the shot comes earlier, so you need less timing. Against
this is the downside that the opponent still has an inner table that
poses a threat, but that's life. So the problem with having a lot
of men on the bar is that they might not enter in time to hit
an outside shot.

If we exclude those cases, then we have a position where the opponent
cannot scramble home while you are on the bar, and any back men
have an exit pathway to join the forward forces. In that case, you
are better off with more back men, since every back man improves your
timing.

The key to playing such a position is to concentrate on extricating
back men one at a time. Avoid playing your forward men, since the
larger the gap between the back and forward forces the longer it
takes to build a prime. JF (2.0) mishandles this aspect of
back-game play, so don't rely on its judgment too much.

Brian