"Eight Ever, Nine Never" is an adage for handling 8- and 9-card suit combinations missing the queen. Holding an 8-card combination like this, it is mathematically better to finesse for the queen (50%):

Dummy
AJ98
WestEast
??????
Declarer
KT76


However, when holding a 9-card combination, it's better to cash the ace and king and hope the queen drops. This is a 52% favorite to pick up the queen, as opposed to 50% for a simple finesse.

Dummy
AK987
WestEast
??????
Declarer
JT52


In the above layout, declarer should play the top two hearts and hope for the queen to fall.

Note that "Eight ever, nine never" is not an absolute rule. The auction and defenders' play may also provide clues about the whereabouts of the missing queen.

See also

Online Audio Lessons by Marty Bergen