This is what's really been confusing me. There doesn't seem to be any rhyme or reason. For example,
Mike Crane was split perfectly fine, Bob Wyant, Bernie Vossler, Sherwood Lidermore all fine. But Tod Shaw, John Markel, Chris Mendell did not split. I checked to see if the ones that split had a space after their last name, but they didn't.
Furthermore, some people who had three names or a middle initial did or didn't split, like "Paul And Anna Marie" gave me Paul And, but Rod And Cindy just gave me Rod.
The error messages I got were:
Executing: calculate field wellparcelloc OwnerLast !Owner!.split(" ")[1] PYTHON_9.3#
ERROR 000539: Error running expression: u"MINNEKINE".split(" ")[1]
traceback:
file "<expression>", line 1, in <module>
IndexError: list index out of range