Simulation bidding
Bridge
programs usually use a set of rules for bidding, or a
large database of bids. For example, if you are
overcaller, and opener bids 1
, there will be a set of
rules that the program follows. One rule might be 'Bid
1
with 10 points and at least 5 hearts'. For a given
hand, the program will always make the same bid because
it steps through the same lines of code. Holding say Axx/KQJxx/Qxxx/x,
it will always overcall 1 because that rule says to.
The program will never change its 'mind'
SIMULATION bidding works differently. This crudely is
what happens. After an opening bid of say 1, the
program deals a number of hands that fit the auction to
date. In this case, it deals hands where RHO opener bids
1, and the overcalling hand is known. After the deals
are made, it assesses whether or not overcaller and
partner might have a fit. Perhaps in this case
overcaller holds Axx/Kxxxx/xxxx/x, and the sampling of
deals suggests that on average, overcaller and his
partner have an average heart fit of say 8.3 hearts.
With this information, those hands are passed through a
double-dummy analyzer to see how the partnership fares
in a heart contract, compared to the opponent's playing
in their contract. Here, the program will probably
decide that it gains more by bidding and playing 1 than
by letting the opps play in 1, so overcaller will bid
1.
However on 'close' decisions, depending on the sample of
hands, overcaller MIGHT decide to pass with this
holding. That means that Buff might 'change it's mind'
on a rebid. On some auctions, it might decide to bid, or
pass, or double depending on the sample of simulated
deals. The auctions are much more cluttered, the
opponents more active, and some bids might seem unusual
or aggressive, but are not so goofy that you wouldn't
see them made in a typical matchpoint game. It's fun.
The program finds lots of penalty doubles, and some of
them will make, but many will not. It might bid one more
even expecting to go down, if that score will be better
than letting the opponents play their contract.
The bidding will not be instant, because Buff 'thinks'
about the bids.
Not all bids are simulated. In highly conventional,
tightly defined sequences, for example Stayman
sequences, the bidding remains rule-based. Here, you
have the option to establish the approximate 'thinking
time' for simulation bids. The TOOLBAR allows you to
extend the thinking time, stop the thinking, and switch
Simulation bidding on or off.