I think around 3 is a good number (for now I only use four stringers); A) Your fave, main player...tuned to whichever tuning you play the most (for me thats EADG on a passive short scale PJ bass with 2 stacked Volume/tones and 1 3 way switch) B) A beater that you use for when you go to places you wouldnt want to lose a fave bass. Or simply a second bass you enjoy tuned to your second most used tuning (for me this is half step down on a passive PJ wired VVT) C) Tertiary bass used for a third tuning option (Drop D for me when I get it soon. Probably will have humbucking soap bars, possibly active pups) How bout you guys? 3 seems like a nice number in my book, considering they will all see playing time. But Im sure many will say the more basses the better. And I know also that many guys only have a bass or two. Backups are always nice though. And I know many of you play extended ranges too.