Tyranitar Moveset Comparison video
https://youtu.be/tqsrmv18Xsw
I hope the link works if not on YouTube my son showed me this video today search funkysho Pokémon you will see it.
I was actually pretty shocked to see B/FB do so well it had higher HP than B/C and all within 1-3 second in time. I have B/C and he is a monster always in my lineup, unfortunately my 93% got IT/FB and has stayed at level 20:(
Answers
Actually the results are not too surprising:
http://pogomoves.com/check.php?lang=en&pkmn=Tyranitar&basic=Bite&charge=Fire+Blast
If you go here, you will find that B/FB has 92% of the offensive potential of the B/SE, and Crunch has 95% and Hence, the bite variants have reasonably similar damage potential, against a neutral target.
The true booboo of fire blast is the type coverage. Being unable to hit any of gyarados, dragonite, vaporeon, rhydon or tyranitar himself for even neutral damage, is a big blow. That 92% could well drop to 85 or something when you are faced with something resisting fire blast.
I'm curious about Tyranitar vs Metagross (Steel/Psychic) in gen3.
StoneEdge is resisted by steel.
B/C on paper should be best, but allowing less dodges can lead to SE steel moves to hit.
B/FB should be good too, I wonder if it might be even better (though no stab) as it allows for more dodges in beetween Bites and hit hard FB.
Theorymon
Speculation