You use analytic Starmie because you get the boost after the opponent switches out of Starmie on the switched in Pokemon.
That and I figure with the right EV investment it can properly survive and counter some speedier stuff like Greninja.
Anyway I just had one of the closest matches I have ever had. And it was a Froslass of all things that was able to kill his Talonflame and OHKO his Dragonite to win me the game (good thing it was holding Never-Melt Ice).
In this other match I made some huge mistakes and lost 4 of my Pokemon without doing much damage at the start. I was able to sweep his entire team with Mega Charizard X. That said about half way though the sweep he sent out a Scizor and I had to use Crunch on it because my health was in the red rendering Flare Blitz suicide. Even with my double Dragon Dance the Scizor survived and used Bullet Punch which I survived with 1 HP (13/15).
WDAG-WWWW-WWW4-MP3P
Without Roost, Flare Blitz is unusable if you need to sweep a team. I think I am going to replace it with Fire Fang. Tough Claws along with Dragon Dance and the possibility of a flinch make me thing it is a viable replacement. Tough Claws alone boosts its power to 86.