What's the difference between SB X and plain SB factor

Some X factors are titled "Super Bowl - X" and some just "Super Bowl" without the X.

All of them start on though...what's the difference between the ones that have an "X" in the name vs the ones that don't?

For example,..my Ronnie Lott has a "Super Bowl-X -.Deep Out Zone KO" x factor and a "Super Bowl-Universal Coverage" X factor.

They both seem to count as X factors , what does the "X" in the title mean?