"Not by a Long Chalk"

Any guesses on the origin of this phrase? I’ve had both sporting and military solutions suggested to me, but none have been very convincing…

This from Brewer:

I beat him by a long chalk. Thoroughly. A reference to the custom of making merit marks with chalk, before lead pencils were so common.

I would bet you are mis-hearing. The common saying is, “not by a long shot”.

Do you think the chalk marks are academically related?
or is this a sporting achievement?
I had assumed the latter, but in that case, on what are the chalk marks being made? (assuming that tarmac & other hard surfaces are relatively recent). Maybe it’s a recent phrase, I don’t know - is it dated in your reference?

(and I’m pretty sure that long chalk =/= long shot, they don’t sound that similar, after all)

Could “by a long chalk” by British? I’m in the United States and have always heard “by a long shot.” Dictionary.com has “chalk” meaning “score or tally” as chiefly British.

Just to add a couple of others, “not by a long sight” and “not by a blame sight” mean “definitely not”. Similar in that they describe the lengths by which something is not.

I’ve always heard it as “long shot”, too. Google gives me about 126,000 hits for “long shot” and only 1,360 hits for “long chalk”, so the former phrase is more common, at least on the web. Regardless, Bartleby.com gives this definition for long chalk:

It also gives this definition for long shot:

Note the definite difference between the two phrases. “Long chalk” means “a lot”. “Long shot” means “not at all”.

I’ve always heard it as “not by a long walk.” With the same meaning as “not by a long shot.”