From: yingst@milori.ccit.arizona.edu (JIM YINGST)
Newsgroups: rec.games.abstract
Subject: Re: PENTE: rules - and ninuku-renju
Keywords: pente
Date: 19 Nov 92 05:22:00 GMT
Distribution: world,local
Organization: University of Arizona
News-Software: VAX/VMS VNEWS 1.41

In article <1992Nov18.142423.17650@pellns.alleg.edu>, neilb@scs.leeds.ac.uk (Neil Bowers) writes...

>Comments are welcome --- does anyone have any more background info on Pente?

It was "invented" in 1974 by Gary Gabrel.  I believe it was originally 
marketed by Pente Games (clever name, that), but it was subsequently taken 
over by Parker Brothers.  I put "invented" in quotes because the game is 
extremely similar to an ancient Japanese game, ninuku-renju (sp?).  
Apparently Gabrel was trying to synthesize elements from go and go-moku, 
and he only heard about ninuku-renju after he had developed the Pente rules.
(I seem to remember this from "The Book of Pente", which I skimmed long ago.)

As far as I remember, the only actual differences in rules between Pente and 
ninuku-renju are:

1) N-r requires exactly five in a row to win, no more, while Pente allows
you to win with six or more in a row.  This is pretty rare, anyway, and I
think anyone who gets six in a row deserves to win. :)

2) N-r does not allow a player to place a stone which completes two 
simultaneous rows of three, if both rows can be expanded into five without 
possibly being blocked.  Pente allows this, and this type of double threat 
is a common tactic in Pente, as shown (next page):

                                            X         X
                                  O         O         O
  OO*        OOO      OOOX      OOOX      OOOX      OOOX      (win)
    O   ->     O  ->    O   ->    O   ->    O   ->    O
    O          O        O         O         O         O
                                                      O
In n-r, player "O" would not be allowed to play at point "*", because there
is no way player "X" can stop one of those threes from expanding into five.
In Pente, it's "X"'s fault for getting in that situation in the first place.
Note that if one of these rows starts off partly blocked, then this tactic
does not work nearly as well, as shown (next page):

                                            X          X           X
                                  O         O          O           O
  OO*        OOO      OOOX      OOOX      OOOX      OOOOX      XOOOOX
    O   ->     O  ->    O   ->    O   ->    O   ->     O   ->      O
    O          O        O         O         O          O           O
    X          X        X         X         X          X           X

In ninuku-renju it would be legal for "O" to play at "*", because it is still
possible for "X" to block the double threes which are formed by the move at
"*".

Interestingly, "The Book of Pente" listed these additional rules as "optional
complications" or some such, without saying they were actually the exact rules
for ninuku-renju.
..

Also, from a later example:
>		.......
>		.XO*X..  <- Moving at the "*" is safe for O.  You cannot move
>		.......     into a capture.

Just to clarify - you can move there; it's just not considered a capture.

Hope this was some help to someone.  Enjoy!

Jim Yingst	yingst@ccit.arizona.edu