CWhite11013:now my ball spin is a 5 I add 5 yds
That number doesn't play that way. The 5 is just a representation of how much spin that club has and seriously changes the yardage, depending on the wind.
CWhite11013: now I take my club distance of 205 yds
This is not as important as knowing how far that 205 club carries. Try plugging that carry number in and see if the shortage makes sense.
The too much math comment was a good one. You can get really frustrated trying to force exact numbers to work. You have to think about how a strong wind like that is going to affect the shot and if you know your carry numbers you'll have a better idea of what to hit.
By way of example, using your example above, I don't use math to figure that out, I think of what club I would hit to get to 175. Happens I have a 180 yard 6i that goes to about 183 with the ball I use and total roll. The carry is only about 176 with no wind so I know whatever I hit, it's going to be bigger than the 6. I could use top spin to force the ball through the wind but I don't think that would help in a wind that strong.
The 5i goes 195 and might be a possibility but that only carries about 185 and with that wind it's surely not going that far. Then again, I don't want it to so this might be the right club.
Now I'm up to a 210 yard 4i which carries about 196. I would use back spin to stop the shot and knock the distance down knowing bs into wind does that. So my choice becomes a full 5 iron with partial back spin or a 4i choked with fbs. This is where the landing plays. Sheesh, more variables. :-)
p.s., I very much like the way my 4i stops dead into wind with back spin so I think I'd probably hit that 4i and back off the swing. JMO.