What flying changes
A walking man can only block a mill threat if it stands next to the point in question. A flying man can block any threat on the board. As a result, a single threat against three flying men is almost never enough: they simply land on the empty point.
The flying side also attacks. Every turn it can complete any two it has on the board, so the stronger side must check each move for a hidden mill against itself.
How the stronger side wins
The method is the double threat. Arrange your men so that one move creates two different mill threats. The flying side can block only one, you close the other and the opponent drops to two men.
Before setting up the double threat, make sure your own position is safe: the flying side's two men in a line with an empty third point are a threat you must cover first. Often the cleanest way is to place a man on the empty point of their line while building your own pair.
How the flying side defends
- Keep two of your men on one line with the third point empty, so that your opponent must spend moves watching it.
- Do not wait passively. Each move, ask whether you can make a two that your opponent must answer.
- Steer for repetition. Three repetitions of a position end the game in a draw, and a determined flying side can often reach them.
Three against three
When both sides are down to three men, both fly. The game becomes a pure race of double threats: whoever first creates two threats at once wins, and the side to move has the advantage. Calculate a few moves ahead; there are few men, so it is possible.
Without flying
If you switch flying off in the table settings, three men keep walking. The endgame then becomes a question of mobility, and blocking the weaker side's last men is often faster than forming another mill. On the six men's board flying is off by default for this reason.
Practise it
The hard problems for nine men's morris include flying endgames where you must win the game, not just form a mill. Try them after a few games against the Knight.