Open Your Big Blue Book to Page 385!

Yarn gauge.  It works!! It works best with worsted spun firm. Oh, Yes! And you MUST pack to refusal. 

This is not some promotional craft council standard for selling yarn, this is a practical way to estimate grist while the yarn is still on the spinning bobbin. This is the nitty-gritty of converting fiber to useful yarn.

Alden's table just goes up to about 10,000 ypp, but if you count carefully, have a good yarn gauge, and pack to refusal, the technique works right on up to 60s (34,000 ypp). For finer grist, metal gauges work better than wooden.) 

The day we talked about this, Alden said, "pack to refusal", perhaps 20 times in 4 hours. Pack to refusal is important, and it is different from the "yarn wraps" of the organizations, that just want to sell yarn to retail consumers.

You need a yarn gauge - just wrapping yarn around a pencil, knitting needle or ruler, will not allow you to pack to refusal. I make my yarn gauges out of rosewood.  The form factor changes depending on what grist I am spinning.  I made another one this morning - it has a 0.25" gap, and a bit of a handle so I can hold it firmly as I wrap the 27 or 28 wraps of yarn, while packing the yarn with my thumb and forefinger. (I want a grist of ~11,500 ypp on average.)

With care and practice a yarn gauge will give a better estimate of the grist of a fine single than a "yarn balance". The only thing better is an accurate scale /accurate length. However, the yarn gauge is not as affected spinning oil or fiber moisture as an accurate scale weight/length.