Traditionally, bulldog refers to the plain-leaf, unifloral hybrids that have large, glossy, long-lasting flowers. If you were to do a parentage tree in OrchidWiz or WildCatt, you'd find some monsterous tree that probably leads back to one or several unknown parents. Of the known parents, you'd eventually see species compositions including spicerianum, villosum, bellatulum, gratrixianum, druryi, boxallii, insigne... For instance, Paph Winston Churchill is 36% insigne, 22% spicerianum, 19% UNKNOWN, 11% villosum, 11% boxallii, remainder bellatulum.
I see you're in the Mid-America region. The MAOC show rules indicate anything that's not a primary hybrid is complex. A primary hybrid is a hybrid composed of ONLY TWO species. I personally disagree with this breakup for ribbon judging- you end up with third generation Lawrenceanum-ish (Maudiae-types) hybrids with 30 generation-old true complexes and Paph. Maudiae gets stuck with the primaries.
-Ernie