Another slack chain question

hippy, what is a chain-stretch measuring tool for by the way?
http://www.kronowit.com/bicycling/chainstretch.html
Bicycle chains don't actually stretch like a piece of leather. What actually happens is the holes that contain the chain's pins elongate over time (go from a circle to an oval) and the cumulative effect makes the chain longer in length.

I guess it's a poorly named version of a Chain Wear Indicator tool:
http://www.parktool.com/products/detail.asp?cat=5&item=CC-3

Quoting from your own link: "Bicycle chains don't actually stretch"