That's actually a very good and relevant question. The 2-point butterfly splice was always used on the Merry Widow. The 4-point splice was used on all other cues. I do not know if the butterfly was sometimes used on non-MW cues as well, but I don't recall seeing it. Of course, someone could certainly have ordered a butterfly-splice shaft for a different cue.
Thanks. Didn't know that. My cue is a "trophy" cue with 4 points and no veneers, but it has the rectangle MOP with player name, date, 2nd place price, and location of tournament. One of my best pawn shop finds IMO.