Wool

Recently I purchased some wool from etsy.  It was a 10 pack of 1 ounce each from different breeds of sheep.  There was a discussion on ravelry about how much you can spin from 800 grams of wool and I weighed in on the different masses of wool and that it would be impossible for anyone to estimate how much a perfect stranger who is not an experienced spinner would be able to spin from 800 grams and it would be impossible to judge for even me (I tend to know how much yardage I get from merino) because the person in question did not know the breed of sheep.  Some people did not think the breed would make any difference, so here is a photo of 4 of the tops I received to illustrate this fact.

From left to right we have one ounce each of: Shetland, Merino, Falkland, and Gotland.
There are other properties of these wools that will determine how much yardage you can obtain.  The most yardage will be from the merino because it will spin up the finest and next would be the Falkland.  The Shetland is very airy but also coarse, so it would be third and make a nice woolen yarn.  It too can be spun pretty fine.  Now the Gotland is very dense.  Trust me, it has the same mass as the Shetland.  The gotland can be spun fine if you have patience, but it will want to be spun thicker than any of the others and because of the density, there just is not enough fiber, no matter how fine, to come close to the merino.  I also doubt it would be even 2/3 of the Shetland yardage.
Having never worked with the Gotland, I would guess that it would make a great carpet yarn.  It appears to have a very long staple (length of the individual fibers) and very little crimp.