[PokerAce]

You are absolutely right that aggression from a loose player is different than aggression from a tight player.

However, I'm not trying to come up with a stat on how good a player plays, just how aggressive.

A loose aggressive player and a tight aggressive player will have pretty similar aggression frequency stats. Look at two examples I posted above:

54/16/1.3 = 42%
22/12/1.2 = 42%

The first player is very loose, and is no doubt a very bad player. However, you know that this player is semi aggressive. The second player is tighter, but he bets/raises/calls/folds just as frequently as the first player. When this player is in the hand, expect his actions to be very similar to the loose player.

This isn't meant to be a universal stat that displays how good a player is, just how aggressive they play their hands. You will need to use it in conjunction with other stats to determine the skill of the player.