There is a technique to evaluate situation valid in all cases except in pre-finishing and finishing states(please go to the specific page) when you have chosen the default option that the player which picks the last match is the loser.
If you master binary algebra, there is a very elegant method to evaluate the situation and search winning strokes. It is presented in a separate chapter.
There are other simpler techniques to learn and which require only knowledge of the basic operations (addition, subtraction, multiplication, division).
We introduce two concepts: the even numbers (multiples of 2: 2, 4, 6 ...) and odd numbers (the other numbers: 1, 3, 5 ...), and the integer division, a division of two integers where we only keep the integer part of the quotient (eg integer division by 5 by 2 gives 2).
We calculate three sums:
- S1 sum of all matches,
- S2 sum of two integer division by 2 of the number of matches in each row,
- S3 sum of the integer division by 4 of the number of matches in each row.
If S1, S2 and S3 are even, the situation is winning.