Opening Rolls

 Opening 64: Make the two point?

 From: William Hill Address: illium@whills.demon.co.uk Date: 13 January 1998 Subject: Re: opening roll 6-4 Forum: rec.games.backgammon Google: B0E19D63966822D21C@whills.demon.co.uk

```Midas wrote:
> I did some rollouts of opening moves a while back and top play for
> this this roll was to make the 2 point. Chuck Bower did a more
> comprehensive rollout in the latest Flint Area Backgammon News and came
> to the same conclusion.  So why is it whenever I look at matches from
> some of the best players they invariably play 24-18/13-9  or 24-14?

Hi midas

Not being an expert I hesitate to comment, but since you asked ...

The advantage of course in making the 2-point is that it makes re-entry of
men from the bar more difficult, however it does tie up two men on a point
that you really don't need to make this early in the game. These men are
probably better disposed of in making the 5,4,bar and 3-points. Also, the
2-point is not part of a possible prime spanning the 8 to 3-points.

I think the thing with rollouts is that the further you are from the end of
a game the less accurate they are, there is a greater margin of error at
least. This means that rolls that are very close together can effectively
be equivalent. I usually consider rolls that are within about 3% of each
other roughly equivalent but this of course depends on the circumstances.

I would imagine that experts still play the two moves you suggested because
they offer greater flexibility with little, if any, sacrifice of equity.
Personally I would probably play the 24-18/13-9 move if I was behind and
wanted to attack the game, and I'd play 24-18-14 if I was well in front and
wanted to consolidate. In a single point game making the 2-point could well
be the thing to do, but with matches of 5 points and more the other moves
are certainly worthy alternatives.

Regards
William Hill, illium on FIBS.
```

 Gary Wong  writes: ```You should take the rollout result with a grain of salt, for the following reasons: 1) Every rollout I've seen has ranked the three plays 24/14, 24/18 13/9, and 8/2 6/2 very close -- within a couple of standard deviations, anyway. The evidence seems to indicate that 8/2 6/2 is probably the strongest play (for Jellyfish), but it is not conclusive. The difference is so small that it would take a huge number of samples to say with any certainty. Besides, "knowing" something is the best move isn't as good as knowing _why_ -- otherwise, how can you make use of the knowledge in other situations? Suppose an extensive rollout concluded 8/2 6/2 is the best move for money -- would you play it at double match point? Leading or trailing post-Crawford? For money against an opponent that you know slots and plays purely, and you know from experience that games against her tend to turn to protracted positional battles where strategic weaknesses will come back to haunt you? For money against an opponent who is scared of blitzes and tends to drop cubes he ought to take when in danger of being blitzed? Knowing all the alternatives and their relative strengths and weaknesses is more valuable, in my opinion. 2) Jellyfish is a very good player in most positions, but it's not perfect. It is known to be somewhat better at blitzes than back games, for instance. 8/2 6/2 strengthens your inner board for a blitz; 24/18 13/9 is somewhat more likely to lead to a back game if your blots are hit. Who's to say that the reason 8/2 6/2 produces more wins for Jellyfish isn't simply because it leads to positions it is good at, rather than being an intrinsically `better move'? > Why is it whenever I look at matches from some of the best players they > invariably play 24-18/13-9 or 24-14 ? I'm no "best player" so to get an answer from an expert you'd have to ask one; however I expect the answer you'd get is that most good humans feel that making the 2 point as early as the opening move is too impure -- it's just begging for the opponent to anchor in front of it and leave you with two chequers out of play. It hurts your future blockading strength, because you already start the game with the 8 point and two points 6 pips apart do not go well together (they can never be part of the same prime). It also hurts your timing somewhat which is an important factor in back games and prime-vs-primes -- the problem is that the men you bury on your 2 point have nowhere useful left to go and force you to play other moves elsewhere on the board which may hurt your position. Having bashed the 8/2 6/2 move so much it's worth mentioning its good points too. It does of course secure another inner board point which is not to be sneezed at -- a stronger board than your opponent is always an advantage and any time you put him on the bar, the more points you have, the less chance he has of entering and the less choice of moves he has when he does enter. This is true whether it's your 5 point or 1 point that's made. If the next few rolls start to suggest a blitz is a good approach for you, you'll be glad you made your 2 point. Overall I prefer 24/18 13/9 on an opening 64 (though I'd play 24/14 at double match point). I wouldn't argue against anybody (or any computer) who played 8/2 6/2, though -- in my opinion the plays are close enough that personal preference can and should decide between them. Making a play that leads to a position you're familiar and comfortable with is more of an advantage to you than selecting a move that Jellyfish rollouts say is 0.002 better. Cheers, Gary (GaryW on FIBS). ```

 Patti Beadles  writes: ```One of the things that I find intriguing about 8/2 6/2 is that it cramps some of your opponent's aces. What does he do with 21, 41, 51 now? Splitting is no longer an option, so the only reasonable play is slotting. But now your board is stronger, which means more good things can happen if you hit him. If his style is to always split with aces, then he's probably going to be on unfamiliar ground after these sequences. Just some random 2 a.m. ramblings, ```

 Jerry Weaver  writes: ```Good point about taking away your opponent's ones. It follows, then, that if your 6-4 is in response to an opening 3-1, you would not make your 2-point, since he now has a good one (man from his 6-point to his 5-point). ```

### Opening Rolls

At different match scores  (Louis Nardy Pillards, July 2002)
Average advantage of winning opening roll  (Chuck Bower, Oct 1998)
Choosing a strategy  (Daniel Murphy, June 2001)
Early game rule of thumb  (Rich Munitz, Feb 2009)
Factors to consider  (Kit Woolsey, July 1994)
How computers play  (Kit Woolsey, Mar 1995)
Magriel's Chapter 5  (Hayden Alfano+, May 2006)
Mloner vs Jellyfish  (Kit Woolsey, Dec 1995)
Nactating a whole game  (Nack Ballard+, Jan 2011)
Nactation  (Jim Stutz+, June 2010)
Nactation overview  (Nack Ballard, Oct 2009)
Nactation--Why use it?  (leobueno+, Jan 2011)
Opening 1's: Split or slot?  (Douglas Zare, Dec 2003)
Opening 21: Rollout  (Stick, Mar 2006)
Opening 21: Split or slot?  (Dick Adams+, Dec 2003)
Opening 32: Rollout  (Stick, Feb 2006)
Opening 43: In GOL online match  (Raccoon+, Feb 2004)
Opening 43: Pros and cons  (Stick+, Jan 2006)
Opening 43: Which split is better?  (Peter Backgren+, Aug 2000)
Opening 43: Which split is better?  (Michael J. Zehr+, Mar 1996)
Opening 51: Rollout  (Stick, Feb 2006)
Opening 52: Merits of splitting  (Peter Bell, Apr 1995)
Opening 53: Magriel's recommendation  (George Parker+, July 1997)
Opening 53: Split to 21?  (Alex Zamanian, Aug 2000)
Opening 53: Why make the three point?  (Kit Woolsey+, Feb 1996)
Opening 6's: Slot the bar point?  (Chuck Bower+, Feb 2000)
Opening 6's: Slot the bar point?  (David Montgomery, June 1995)
Opening 62: Could running be best?  (Gary Wong, Sept 1997)
Opening 62: Split, run, or slot?  (Chuck Bower, May 1997)
Opening 63: Middle Eastern split?  (Mark+, Apr 2002)
Opening 63: Slot the four point?  (Dennis Cartwright+, Mar 2002)
Opening 64: Make the two point?  (William Hill+, Jan 1998)
Opening 64: Make the two point?  (Darse Billings, Feb 1995)
Opening 64: Rollout  (Peter Grotrian, Jan 2006)
Opening 64: Split to 20?  (Peter Bell, June 1995)
Opening 64: Three choices  (Brian Sheppard, July 1997)
Opening 65: Becker on lover's leap  (Jeffrey Spiegler+, Aug 1991)
Opening 65: Computer rankings  (Chuck Bower, Jan 1997)
Opening rolls ranked  (Arthur+, Apr 2005)
Rollouts of opening 21 and replies  (Alexander Nitschke, Oct 1997)
Rollouts of openings  (Tom Keith+, Jan 2006)
Rollouts: Expert Backgammon  (Tom Fahland, Aug 1994)
Rollouts: Jellyfish 3.0  (Midas+, Sept 1997)
Rollouts: Jellyfish 3.0 level 6  (Chuck Bower, Feb 1999)
Rollouts: Snowie 4.1  (Rene Cerutti, Apr 2004)
Slotting the four point  (Joe Loria+, Oct 1999)
Snowie's openers and replies  (rcerutti, Feb 1999)
Splitting versus building  (Dave Slayton+, Aug 2000)
Splitting versus slotting  (Daniel Murphy, Apr 2001)
Splitting versus slotting  (Daniel Murphy, Sept 1997)
Trice's rankings  (Marty Storer, Feb 1992)