Possible Clues:

• Dick Francis thriller title
• No racehorse alive is one
• You'll definitely be on a winner with this written apology for being late
• A shoo-in from Francis
• 29 broadcast without a da capo? Sure thing!
• Sure thing sounding moribund - bet on it
• Sagan would have had our opinion of him
• Democrat reacted strangely to sure-fire winner
• Favourite invalid with doc?