My friends have explained how the law operates but here's the citation from §6428(d) in case it helps [emphasis added]:
Eligible individual For purposes of this section, the term “eligible individual” means any individual other than -
(1) any nonresident alien individual,
(2) any individual with respect to whom a deduction under section 151 is allowable to another taxpayer for a taxable year beginning in the calendar year in which the individual’s taxable year begins, and
(3) an estate or trust.
Still an AllStar