a FIDE pairing engine for the Dutch Algorithm
version 2.0 (alignment to 2017 Rules) available
the name of a program that implements the pairing rules of the Swiss
System called "Dutch", as described in the FIDE handbook,
(for a pdf version of the entire section C.04, look here).
is authored and intellectually owned by Roberto Ricca, former
programmer, International arbiter and currently Secretary of the FIDE
of Pairings and Programs”
formerly known as “Swiss Pairings Programs”.
from concatenating the first and the last letter of the author's
three nephews, Johanna, Victoria and Francesco. Therefore in its
correct spelling J, V, F are all capital letters. Of course,
depending on the circumstances, also javafo
proper spellings, but please never use Javafo, as J, V and F have all
the same dignity.
system has been brought to FIDE by the Dutch International Arbiter
Geurt Gjissen. It is the main pairing system supported by FIDE. In
reading its rules, there is the constant impression that it is a
software algorithm being presented. Never an impression was more
correct! In fact, the legend says that first came the Dutch Algorithm
(and the Swiss Master program that was implementing it), and then
FIDE rules were modelled on it.
bit of history
quite a long time, the existing dichotomy in the Dutch rules was the
main source of confusion for both arbiters and programmers: should
they follow (implement) the rules described in the handbook or behave
as Swiss Master was behaving (build a clone for programmers)?
2011, the FIDE handbook (at that time, section C.04.1, called “Swiss
System Based On Rating”) was not very helpful, as some of its
rules, perhaps because of how they were born, were ambiguous when not
inconsistent. The end-result of this was that there were some
situations (rather extreme situations, indeed) in which different
officially FIDE endorsed programs produced different pairings, even
in top brackets!
2011 to 2013, at the FIDE Congresses in Krakow, Istanbul and Tallinn,
the SPP Commission performed some heavy rewriting on the Dutch rules
and, although some things can still be written in a better way, at
least the grandest part of the ambiguities was removed (hopefully,
all of them).
by the role that its author has in the SPP Commission, JaVafo has
always been the first pairing engine available that was following the
clarified interpretation of the Dutch rules. Also mentioned in the
FIDE handbook (section C.04.4 – The endorsement procedure),
JaVaFo has been the ideal benchmark against which to test other
advanced user manual is available in various formats:
current version of JaVaFo is 1.4 (made available on March 30th,
is written in Java (there are no relationships between the names Java
and JaVaFo - it is just a coincidence). Therefore, a computer needs a
Java Virtual Machine (JVM) to run it. Very likely, it already has it.
To find it out,
Control Panel and
look for a "Java"
icon. If it is there, Java is already installed, and just its version
may need a check: double-click on the Java icon, select tab General,
then press button About:
a pop-up window will report the current version (which should be 5 or
greater to ensure proper working of JaVaFo).
there's no "Java" icon up there, just go to the official
java site (www.java.com),
follow the instructions to download the latest release of Java for
the computer operating system, then install it using an
'Administrator' account - this is a very simple and straightforward
operation, which will require just a few minutes.
all of this has been done, a computer is ready to run JaVaFo.
long as it is pronounced properly (again,
it is yäväfö')
and spelled correctly (again: javafo, JaVaFo and JAVAFO are ok,
wrong!), JaVaFo is free of charge. Just mention this page when using
it in a commercial product.
report any problems to email@example.com. The program was extensively
tested, so no problem is expected - but, as the saying goes, never