I get it but regard it as a kind of rule of thumb that works out. The math is favorable. 9' table has a 50" surface width. 14.5 ft is 174". Minus playing surface = 124". Divide by the two sides and you're at 62" clearance for a 4" back swing if you're shooting straight off the rail. Tight, maybe, but how much back swing are you ever using when shooting off the rail? I'm either jacked up or taking a careful short level stroke trying not to miscue.
I'm fortunate that my room is 15'6". But on the wall I wanted to be close to, which is the long side, I centered the table on 19' relative to that wall and there's plenty of stroke room on that side.
Now, actually using a room that is 14.5x19 means having nothing in that room except a pool table. My room is something like 22"6' long and I'm going to have to be creative getting a work bench and seating in there.
As I said, my answer wouldnt make sense. Let me say another way... adding 5' clearance does not ever get you 14' 6" x 19'. Ever. Impossible.
if you add 5' clearance to the length of a table, and you end up with an actual measurement of 19' (completely possible), then the width would have to be 14' 10", not 14' 6". That's the math if the table and nothing to do with personal preference.
So if we go by the helpful "rule of thumb" of adding 5' clearance (or 10' to the table sizes or whatever), you'll always be starting with less room on the width compared to the length of you simply use 9 x 4.5
As your references . Always.
So if someone starts to buy a house, I think the "rule of thumb" better make sense. Adding 10' clearance is great, but you actually have to measure your table or do the math. Or else you might get a surprise when you compromised a little on the size and end up scratching your head saying "why don't I have as much room on the width as I do the length?"
If you come up with a length of 19' (great!), then the corresponding width has to be 14' 10", not 14' 6". That's the math.
Freddie <~~~ still won't make sense