The Crossing the T effect occurs when a force is firing from a flank of its enemy who are in line formation or when firing along the length of the enemy when they are in column formation.
Crossing the T comes from the nautical back ground in the Army it is more correctly called Enfilade fire which comes from the French enfiler - or to skewer.
The effectiveness of Enfilade comes from several factors:
- For the assaulting side; in the main, only elevation has to be changed thus reducing the firing equation to one dimension
- The reduced traverse means targets are acquired more quickly
- Rounds that miss the target have a high probability of continuing on to hit other enemy targets further along in the enemy formation
- The effective fire of the enemy is reduced to single point, as intervening enemy troops obscure their comrades fire.
- All the effective fire of the enfilading force is applied