Working at night with matchsticks on the table, he eventually came up with what he called "Beam Defense Position", but which soon became known as the "Thach Weave". The theory behind the beam attack was predicated on the 2 plane element of the Finger-Four Formation. It was executed either by two fighter aircraft side-by-side or by two pairs of fighters flying together. When an enemy aircraft chose one fighter as his target (the "bait" fighter; his wingman being the "hook"), the two wingmen turned in towards each other. After crossing paths, and once their separation was great enough, they would then repeat the exercise, again turning in towards each other, bringing the enemy plane into the hook's sights. A correctly executed Thach Weave (assuming the bait was taken and followed) left little chance of escape to even the most maneuverable opponent.