Yep a range of factors have to be considered.
Head winds reduce roll out (even when using top spin) or add to how much a ball will back up it it's hit with spin.
Wind with a shot adds to roll out and reduces any back up or stop from backspin.
So you can't use the same 3 mph of wind = 1 yard factor for both head wind and follow wind.
One factor we can't account for because of it's randomness is VEM as it relates to the Forgiveness and Precision rating of the equipment you are using.
VEM
WGTniv:Forgiveness shifts the precision
circle left or right (and usually short) depending on how much you mishit and
what the forgiveness rating of the club is. Clubs with lesser forgiveness
ratings shift the circle left/right more on mishits.
This is why (especially on low precision clubs) you can mishit
slightly right of the mark and have the ball go left instead. Mishitting
right shifts the circle to the right, but part of the circle is still
"leftover" on the left side of the flag, so it has the potential to
land there.
WGTniv: The game is pretty simple.
Precision controls your accuracy.
Imagine it's like a circle that surrounds the flagstick when you
aim at it. The size of that circle is related to the precision
rating. The higher the rating the smaller the circle.
Your ball can land anywhere in the circle on a dinged shot (left
or right, long or short).
It will ALWAYS land in the
circle on a ding shot, though sometimes it may land in the center of the circle
and sometimes it may land on the very outer edge or anywhere in between those
two points. When it lands on the outer edge this is what you guys have
come to know as "the beast".
Was the shot pre-programmed? Does it know you're standing on the
17th hole at Kiawah?
No, it's just unfortunate timing.
The result you see is the logical spread dictated by the precision
rating of the club over 100 or 1,000 or 10,000 shots taken on the site.
No matter how big or small the sample it's amazingly consistent
because it is after all only a simple mathematical formula.
The shot data is spread out amongst all users, so there will be
times when you run into a lot of "edge cases" (aka deviations, aka
outside edge of the precision circle) and times where you seemingly can't miss
the center (even when you mishit).
This is the ebb and flow of the game and it's always been
there. In the short term you will have "bad" days and
"good" days. In the long term (providing they are using the
same clubs) any one player will see the same amount of "edge cases"
or "deviations" that the rest of the players do.