If you desire to know if any one of your men has the move of any man on the other side, examine the position of both. If there is a black square on the right angle under his man you Have the Move. For instance, you have a black man on 30, and white has a man on 3. The right angle is the black square between 31 and 32. With your man on square 29 or 31 the right angle would be found on the black squares on one or other side of the straight line below the white man, and he, therefore, would Have the Move. The value of this plan is that it holds good with any number of men.

A Third Plan.—Count the men and the squares. If the men are even and the squares are odd, or if the squares are even and the men odd, you Have the Move. With even men and even squares, and odd men and odd squares, the move is on the other side.

To apply this theory. When you have the move do not exchange, if you can avoid it, or you may lose the move. For example, place the men thus:

The Move.—White to play and win.

When all the men, both Black and White, on the lettered column (a, b, c, d,) are added up, the total is odd, and the side having to play Has the Move. If no men are on the lettered squares, then take the figured squares, 1, 2, 3, 4; but do not combine the two. Apply the theory to the above position. We find that there being 9, an odd number of men, on the lettered columns, White Has the Move, and having it, would win:

White. Black.
28to24—1—8to12
30to26—2—2to6
24to19—3—6to10
21to17—4—9to13
26to22—5—1to6
32to28—6—6to9
28to24—7—

What, now, can Black do but play, and lose a man and the game? He has but two squares, 15 and 11, open to him. His defeat is decisive and complete.

TO REGAIN THE MOVE.

Change man for man till only one capturing piece remains on the board. Suppose Black had men on squares 12 and 15, and White had men on 24 and 28. What should White do? Nothing more simple. He plays from 24 to 19. Black must take the offered piece and be taken, when his remaining man on 12 is fixed by the White on square 19.