If you believe in omens, Tannehill's #17 portends well for his career success.
First consider our drafted QBs: the two best ever: Marino and Griese respectively wore #13 and #12. Then there was the late David Woodley who went 27-12 while wearing #16. Don't forget our backup extraordinaire, Don Strock, #10, who went 14-6 over his long career with us. Even backup Damon Huard, #11, drafted in '98, started 6 games and went 5-1. Scott Mitchell, #19, didn't set the world on fire here before he snookered Detroit into that FA contract, but still he threw 12 TDs to 8Ints.
On the other, darker side of that draft road we have: John Beck #9, wee Patty White #6 and Henne#8. I've likely missed a few others unlike Josh Heupels who never saw the field so chime in.
For those who were initially drafted or signed elsewhere before reaching Davie, it's a bit murkier:
On the very bright side there's Earl Morrall #15 and Chad Pennington #10, arguably 2 of our 5 or 6 best QBs in franchise history. To a lesser extent although he won 9 games for us in his short pit stop is Gus Frerotte #11. Conversely, moderate positive exceptions to this Double Digit Hypothesis would include Jay Fieldler #9 and Matt Moore #8
Free Agents who negatively lived up to their assigned numbers include Culpepper #8, Lucas #6, Harrington #3
... and the outright awful or circumstantially underwhelming double digit jersey exceptions coming from elsewhere include Cleo Lemon #17 (hopefully not an omen), Thigpen #16, Trent Green #10, Brian Griese #14, Sage Rosenfels #18, and AJ Feely #13
So obviously 2 of our best ever QBs, FAs Morrall and Pennington experienced their success for us while wearing double digits on their backs, so that's relevant despite the many FA exceptions, but largely it's the homegrown under center hypothesis that has held up pretty firmly for those drafted QBs who precede T-Hill.
I understand that the assignment of numbers is somewhat either arbitrary or a carry-over from college and an argument can be made that the foregoing is hogwash. However, there's no denying that our greatest QBs whether drafted by us or not, all sported double digit numbers on their backs. It just is what it is. Although he's got some big shoes to fill, hopefully Ryan will carry on in that grand tradition.