| 100% | MORA | 4 | Last name of father-and-son N.F.L. coaches |
| 67% | STILLER | 7 | Last name of Jerry and Ben, acting father and son |
| 67% | ARKIN | 5 | Last name of father-and-son actors Alan and Adam |
| 67% | GRIESE | 6 | Last name of father-and-son quarterbacks Bob and Brian |
| 65% | ALDA | 4 | Last name of father/son actors Robert and Alan |
| 62% | BUSH | 4 | Last name of father-and-son US presidents |
| 59% | ONEAL | 5 | Last name of father-and-daughter actor Ryan and actress Tatum |
| 59% | MAHAL | 5 | Last name of father-daughter singers Taj and Deva |
| 59% | SILAS | 5 | Surname of father-and-son N.B.A. coaches Paul and Stephen |
| 58% | BOHR | 4 | Family name of father and son who won 1922 and 1975 Physics Nobel Prizes |
| 54% | DITKA | 5 | N.F.L. Coach of the Year in 1985 and 1988 |
| 52% | ALI | 3 | Last name of father-and-daughter members of the International Boxing Hall of Fame |
| 52% | MADDEN | 6 | N.F.L. video-game franchise named for a storied coach and commentator |
| 51% | MORA | 4 | Either of two N.F.L. coaches named Jim |
| 50% | ASSAD | 5 | Name of father-and-son world leaders |
| 48% | OBAMA | 5 | Last name of Sasha and Malia |
| 48% | BAGGINS | 7 | Last name of Frodo and Bilbo |
| 47% | ALI | 3 | Last name of boxers Muhammad and Laila |
| 47% | OBAMA | 5 | Last name of teenagers Malia and Sasha |
| 47% | BABBITT | 7 | Last name of 30- and 35-Across |
| 47% | COEN | 4 | Last name of filmmakers Ethan and Joel |
| 47% | GALLO | 5 | Last name of winemakers Ernest and Julio |
| 47% | COEN | 4 | Last name of filmmakers Joel and Ethan |
| 47% | LEE | 3 | Last name of filmmakers Spike and Ang |
| 47% | MILLER | 6 | Last name of Sienna, Ezra and Wentworth |
| 47% | MARA | 4 | Last name of actresses Rooney and Kate |
| 47% | CRANE | 5 | Last name of TV's Niles and Frasier |
| 47% | TAM | 3 | Last name of Simon and River, on "Firefly" |
| 47% | OLSEN | 5 | Last name of twins Mary-Kate and Ashley |
| 47% | LEE | 3 | Last name of martial artists Bruce and Brandon |