If, however, the 4 ships of _A_ "flank" or "T" the ships of column _B_, as shown in Fig.

2, and concentrate on the leader of B, they thereby isolate the other ships, and practically nullify their ability to fire at _A_.
[Illustration: Fig.

2] This effect is approximated by an approximate "T-ing" or "flanking," such as is shown in Fig.

3; because the average distance from the ships of _A_ to the leading ship in _B_ is less than the average distance from the ships in _B_ to any ship in _A_; and because the direction of fire from each ship in _A_ is more nearly abeam than is the direction of fire from the ships of _B_.

These positions are very difficult to gain, even if _A_'s speed is considerably greater than _B's_; since all _B_ has to do to prevent it is to head to the right, unless shoals or other dangers such as enemy battleships, _C_, are on that side, co-operating with _A_.
[Illustration: Fig.