Ozzy Osbourne’s lawsuit against Black Sabbath guitarist Tony Iommi over ownership of the band’s name uses popular perception to counter the reality of the metal titans’ history.

Thanks to the shrewd marketing of wife-manager Sharon Osbourne, Ozzy has become a brand name. His addled mumble has become so recognizable he spoofs himself in a cell phone commercial.

But that hardly makes him 50 percent of Sabbath, and that’s the share of the name Osbourne wants, according to Billboard.

Ozzy was 25 percent of the original Sabbath - no more and possibly less.

Bassist Geezer Butler was the primary lyricist and it’s Iommi’s monolithic riffs that are the most recognizable aspect of the sound. Butler and drummer Bill Ward created the template for heavy rhythm sections, although with far more swing and far less plod than their less mindful followers manage.

Ozzy’s notoriety in the ‘80s had as much to do with his bat-biting antics as with his albums, which declined considerably after the death of guitarist Randy Rhoads in 1982. But he became a star while Sabbath - with Iommi as the only constant - struggled through near-constant lineup changes.

They were better together, but that doesn’t diminish the contributions of the other 75 percent of the band.

In a statement written as a letter to Iommi, Osbourne says “the trademark should be owned by the four of us equally.”

But he wants 50 percent.

Looks like Ozzy’s math is as bad as his enunciation.