Fact - Fiction - Phantasy
Deep within the labyrinthine halls of ACBL Headquarters,
hidden in a dark, little-used back office that few know about, it exists - the evil
ACBL computer deal-generator.
Attended by a small group of wicked, twisted
gnomes, the leering machine spews out tragic deals one after another. The computer's
demon brood lurks in the ACBL warehouse until the day that it is shipped to a tournament
and unleashed on a group of unsuspecting players. The cries of horror can be heard
throughout the playing area.
Aarrgghh! The trumps split 5-0!
Egad! I was 6-6 in the majors and partner
was 6-6 in the minors!
The finesses all lose!
The cards are all running the other direction!
Deep within the bowels of ACBL headquarters,
the satanic computer utters a malevolent laugh.
Yes, the preceding is a joke, but anyone familiar
with the tournament scene knows that there are plenty of members who believe this
scenario, or something close to it, might well be true.
Let's face it, computer-generated hands have
a bad reputation in some circles --- undeservedly so. "These computer hands!"
is a common cry, but how different are "computer hands" from people-dealt
hands? Also, how does ACBL create these deals?
Let's tackle the second question first. It
is a simple matter for a computer to deal a set of 52 cards. To explain how this
process works, using an oversimplified analogy, consider how a mailman places letters
in a set of post office boxes. Each piece of mail has an address, and the mailman
places each piece in the correct box.
Similarly, each card of the deck is randomly
assigned a value which determines which "box" (hand) it will be dealt to.
There is a catch, however, and it has to do with the word "randomly." It
is important that the computer performs this task in a random fashion. Otherwise
there is a risk that the same set of hands will be generated more than once.
Many computers use their internal clocks as
a "random" starting value to assign each of the cards an "address."
In practice, however, this method isn't sufficiently random enough. The software
that ACBL uses to generate deals, therefore, requires an additional step. The staff
person whose job it is to create the deals must physically deal out a set of 52 cards,
just as you would do at the bridge table. The four hands are entered into the computer.
This information, along with the time at which it was entered, create the starting
value for the process and ensures that it is completely random. For the more technically
inclined, the random number generator uses a linear congruential algorithm that will
repeat after 2 to the 47th power (140,737,488,355,328) deals have been generated.
Returning to the question of whether computer-dealt
hands are different from people-dealt ones, remember the great emphasis placed on
creating a random deal. To create a random deal manually, players must give the deck
a thorough shuffle at least seven times to guarantee that the cards are mixed. It
is common, however, to see players shuffle the deck only two or three times before
dealing. This is not a random deal.
Although it is beyond the scope of this article
to demonstrate, it has been suggested by various mathematical authorities that this
inadequate shuffling may lead to "flatter" distributions. In other words,
suits may break evenly more often than expected. Players who are accustomed to their
trump suits dividing evenly all the time because of inadequate mixing seem genuinely
offended when they encounter a 4-1 trump split in a computer-dealt game, even though
that division will occur 28% of the time.
"Computer-dealt hands!" they mutter,
but in reality they're just getting a dose of a truly random deal. Another factor
which causes some players to believe that computer-dealt hands are different from
people-dealt ones is that hand records are usually available after a computer-dealt
session. Players then have the opportunity to see all the cards of every deal, and
some of these players will use the hand records as "proof" of the "strange
distributions" supposedly caused by the computer. If these same players could
see hand records from their local club games, they would find that "strange
distributions" occur in hand-dealt games as well.
Does anyone at ACBL look at the deals in order
to throw out "boring" ones or to include particularly frustrating ones?
Never. Repeat: Never. In fact, only two people at ACBL are even permitted to see
the hand records. One is the person whose job it is to set up the computer to generate
the hand records. The other is the print shop manager who cuts, wraps and labels
the hand-record packages. Neither is a bridge player. The hand records are then sealed
and shipped to the ACBL warehouse. When needed, they are mailed to the tournament
official who orders them. No one at ACBL ever manipulates the deals.
Sometimes players complain that the cards seem
to run one direction (usually the direction of their opponents).
"North-South had all the cards!"
This does occur sometimes, but it happens in people-dealt games as well. George S.
Kaufman, the famous New York dramatist and bridge expert, once quipped that clubs
should post which way the cards are running as a courtesy to the players. He said
this, however, during the 1930s. People have been complaining that their opponents
hold all the cards since the days of whist.
Finally, let's not forget the advantages of
computer dealing. At NABC+ events, the duplimate machine actually pre-deals several
sections of hands based on computer records. Without computers, hand records would
not be available at tournaments. It would be too time-consuming to copy all of the
information from people-dealt hands.