5 research outputs found
11 x 11 Domineering is Solved: The first player wins
We have developed a program called MUDoS (Maastricht University Domineering
Solver) that solves Domineering positions in a very efficient way. This enables
the solution of known positions so far (up to the 10 x 10 board) much quicker
(measured in number of investigated nodes).
More importantly, it enables the solution of the 11 x 11 Domineering board, a
board up till now far out of reach of previous Domineering solvers. The
solution needed the investigation of 259,689,994,008 nodes, using almost half a
year of computation time on a single simple desktop computer. The results show
that under optimal play the first player wins the 11 x 11 Domineering game,
irrespective if Vertical or Horizontal starts the game.
In addition, several other boards hitherto unsolved were solved. Using the
convention that Vertical starts, the 8 x 15, 11 x 9, 12 x 8, 12 x 15, 14 x 8,
and 17 x 6 boards are all won by Vertical, whereas the 6 x 17, 8 x 12, 9 x 11,
and 11 x 10 boards are all won by Horizontal
New Results for Domineering from Combinatorial Game Theory Endgame Databases
We have constructed endgame databases for all single-component positions up
to 15 squares for Domineering, filled with exact Combinatorial Game Theory
(CGT) values in canonical form. The most important findings are as follows.
First, as an extension of Conway's [8] famous Bridge Splitting Theorem for
Domineering, we state and prove another theorem, dubbed the Bridge Destroying
Theorem for Domineering. Together these two theorems prove very powerful in
determining the CGT values of large positions as the sum of the values of
smaller fragments, but also to compose larger positions with specified values
from smaller fragments. Using the theorems, we then prove that for any dyadic
rational number there exist Domineering positions with that value.
Second, we investigate Domineering positions with infinitesimal CGT values,
in particular ups and downs, tinies and minies, and nimbers. In the databases
we find many positions with single or double up and down values, but no ups and
downs with higher multitudes. However, we prove that such single-component ups
and downs easily can be constructed. Further, we find Domineering positions
with 11 different tinies and minies values. For each we give an example. Next,
for nimbers we find many Domineering positions with values up to *3. This is
surprising, since Drummond-Cole [10] suspected that no *2 and *3 positions in
standard Domineering would exist. We show and characterize many *2 and *3
positions. Finally, we give some Domineering positions with values interesting
for other reasons.
Third, we have investigated the temperature of all positions in our
databases. There appears to be exactly one position with temperature 2 (as
already found before) and no positions with temperature larger than 2. This
supports Berlekamp's conjecture that 2 is the highest possible temperature in
Domineering
Snakes in Domineering games
AbstractWe give a complete characterization of repeating Domineering snake positions