Wind Knots

If I remember correctly, your book Practical Fishing Knots says a knot that slips is a weak knot. Why does a wind knot so badly affect the strength of the leader when it's so small that it can't slip?

Q:  If I remember correctly, your book Practical Fishing Knots says a knot that slips is a weak knot. Why does a wind knot so badly affect the strength of the leader when it's so small that it can't slip?

- John Edwards
United Kingdom

A:  Actually, the wind, or overhand, knot may be small, but high-speed photography shows that it continues to slip until it breaks. Wind knots can reduce line strength by as much as 50 percent.