Tactical Points/Delay to TP (pre-Apr. 2006 update)

From FFXIclopedia, the free Final Fantasy XI encyclopedia

Prior to the Apr 18, 2006 update, TP and weapon delay had the following relationship:

Delay	Tactical Points
0 - 180	5.0
180 - 480	5.0 + [(Delay - 180) / 256] * 6
480 +	6.0 + (Delay / 80)

Note: TP is rounded down to the nearest tenth.

This TP system favored fast weapons, and penalized the slowest weapons. The further below 180 a player could push his weapon's Delay, the faster he would gain TP. The player would be increasing his attack speed while still gaining a constant 5.0 TP. This fact was exploited frequently by Thieves, who would set Ninja as their support job in order to Dual Wield low Delay daggers.

On the other hand, weapons of higher Delay gained less TP per point of Delay than weapons with Delay closer to 180. For example, a weapon with 240 Delay would gain 6.4 TP per hit, but a weapon with 480 Delay would gain 12.0 TP per hit. In addition to that, the formula used to calculate the TP for weapons with more than 480 Delay required more Delay to cause a 0.1 increase in TP gained per hit.