Google's Hot Clues

How high can a clue phrase get in Google Hot Trends?

From scanning the first two weeks of results, I'd say about 16th on average, with significant variation.

Tuesday, May 15, 2007: 17. indian bean tree

Wednesday, May 16, 2007: 18. picnic playwright

Thursday, May 17, 2007: 25. trojan wise man

Friday, May 18, 2007: 13. 1999 ian mckellen film

Saturday, May 19, 2007: 14. scottish royal house

Sunday, May 20, 2007: 25. author janowitz

Monday, May 21, 2007: 15. son of judah

Tuesday, May 22, 2007: 35. harry belafonte s daughter

Wednesday, May 23, 2007: 28. singer irene

Thursday, May 24, 2007: 11. deuterium discoverer

Friday, May 25, 2007: 5. vietnamese dress

Saturday, May 26, 2007: 7. hermes winged sandals

Sunday, May 27, 2007 (1 PM PDT): 11. composer scarlatti

Any patterns? Any suggestions why these phrases, and not others, got so high?

[By the way, I define a "clue phrase" as a phrase that looks like a crossword puzzle clue and that doesn't have a logical explanation in the daily news or blogosphere. Of course, some phrases may appear to be clues though they're not -- or vice versa. The phrases I've listed are my best guesses at the top clue phrases.]