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PERTO.EXE ReadMe
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"PERTO" is short of "repertoire." It starts with a single board position
(expressed as the end of a line of notation) then works backwards through
game collections to find ALL POSSIBLE move sequences that could reach the
position. In doing so, it identifies all "stoppers" as well. A stopper is a
move that would take one, irretrievably, away from the position. The idea
is to help OTB players establish an opening repertoire and to help
correspondence players achieve a winning position.

PERTO can accept multiple game collections--in fact it will produce better
results the more games there are. You can open up to 10 game files--or up
to 8000 total games.

To understand what game files should make up the search criteria it is
useful to think of a pyramid: at the top (the first file searched) there
should be a tight collection of games very similar to the line being
searched for. This might be accomplished with opening collections or by
selecting out games from your database having the associated ECO.

Next would come games of a more general classification but still similar to
the line of interest. If the first file was organized by ECO, the second
might be by opening name.

There can be several stages but at the "bottom"--the last search
file--should come a mixed collection containing all openings. This is not
only because transpositions can come from anywhere, but also because the
general collection helps fill in most accurately the average
"alternative-expectation" number for moves early on in the chosen line.

	[To build a general collection I selected all games from the
	past year from my Chess Assistant database. (Selecting by year
	tends to avoid bias toward certain openings.) These games were
	printed as PGN, then HighRank.exe was used to weed out the
        amateur games. Next the collection was randomized with an option
	of PGNSrt.exe. Randomization is not necessary for PERTO but it
	does provide a quick way to skim off smaller collections for
	other projects--I am able to select x-number of games off the top
	of the large PGN file.]

Incidentally, the order in which collections are read is unimportant to
PERTO. It's just more useful to think of them when arranged in a
specific-to-general sequence.

As PERTO begins an analysis, it reads the line (position) file first (the
top line/game) then searches all the files for move sequences that reach
it. The line position ITSELF MUST be in one of the collections or there
will be NO OUTPUT. If unsure, define the GamesU4 file a second time as a
member of a collection (as well as the file which defined the original line
for search).

Analysis goes to Trial.txt and TrialOut.txt. File names I use here are
defaults--other names can be chosen.

You can store multiple lines of interest in the search criterion file
(GamesU4.txt). Only the top one will be used in a search.

With some study the analysis files produced in Trial and TrialOut.txt
should make sense (for help see Reports.txt). ChessU3 and ChessU4 can read
the notation style created in Trial.txt.

PERTO can handle annotated games.

	-Paul Onstad 70641.3236@compuserve.com

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