shorthanded vs full ring

[NYplayer]

Here is how I think about opening from the CO or BU. I have a range that I believe is correct against unknown and/or very good players. I then take into account how much the blinds defend. I tighten up if the sb folds less than 75-70% and if the BB folds less than 40%. I'll loosen up if the bb folds over 50% but given a bb who folds about 40-45% (which I believe is optimal) i wont change my standards even if the SB is very loose. I will also take into account how aggressive and tenacious a player is. If I'm up against a BB that goes to SD 45%+ I'll throw away the 78s and 97s type hands in the CO because its important to have a sense of how often you can win without showdown when deciding what types of hands to play.
if you are in the CO and the button is very loose and floats and or 3 bets a lot you obviously have to tighten up. I think if you take these factors into account it doesn't matter how many players are at the table.