Game Development Reference
Crossing the T produces three moves but stops there.
Figure 7.4, this move often creates a far better second move the 84.3 percent of
the time there is a nearby mine. On average, there are 1.66 mines in the sur-
rounding squares, making the most common revealed number a 1 or 2. A
revealed 1 makes the risk on the second move 12.5 percent, almost half the risk of
a random move. A revealed 2 means a risk of 25 percent. Although this is worse
than the 20.7 percent risk of a randommove, this is mitigated when you consider
the gain of a well-placed second move. If the revealed number is less than 3, then
a second move should be the neighboring square that is on the edge. There is a
chance the second move will reveal a 0 and four free moves, a happy event that we
will ignore for now. The second move cannot reveal a number higher than
the number revealed by the first move. If the first move revealed a 1, the second
move is a mine, a 0 or a 1. If these two squares leading out of an edge have the
same revealed number, then there are three safe moves that ''cross the T'' of
the first two moves. The number revealed by the second move is constrained
by the number revealed by the first move, so if the second move was safe enough
to take and it did not fail, it has a very high chance of giving the three free moves.
The idea here is that we have created a low-risk second move with a possible
three- or four-square payoff.
One Square Diagonally Away from a Corner
All the initial numbers for this case compute the same as in the previous case, but
the location of the second move should be the corner. As shown in Figure 7.5, a
The corner produces five moves and more after that.