If you are a thriller or mystery writer. Lead with your protagonist! Think about it: you read blurbs on books that say, “A Phred Pharquarte” novel, or somesuch. Readers who like your principal character are going to go back and back to read more action about him/her. I became enamored of the Travis McGee character years ago. I have all the books in which he was the protagonist.
It makes sense, when you’re trying to sell an agent or editor on your book to begin your “pitch” with what they can sell.