wow. never looked at it from that mathamagician standpoint. =)
it is worse- because it leads to the practice at ditmars of having 2 trains come in, then they depart within 2 minutes of each other. of course, you lose some time here and there, and the back up at astoria blvd. to get into ditmars happens. this is pretty common in evening and afternoon rush.
plus, the car cleaners have to run around like a race car pit crew to get the cars cleaned before they roll, and you KNOW them guys ain't going to hussle that fast, especially not all day... so that adds a bit of grime at times...