>>18482676Clamp, as with all trapping moves, are good on mons that lack the power to 1HKO/2HKO most mons, have the bulk to survive 4+ turns, and gain something from having a mon stuck in (Perish trapping, boosting, etc).
What mon are you facing that you cannot 2HKO with a Shell Smashed Cloyster that you would prefer to slowly whittle down HP by %, all the while exposing your own frail Cloyster to retalitatory Attack, most of which will KO it (even through its good Def due to no defensive investment and lack of recovery).
Clamp was good in Gen 1 since Gen 1 wrapping mechanics prevented opponents from acting, meaning you could easily wrap things to death.
Trapping is only viable in Gen 6 due to the boost in damage + 4/5 turn guarantee, but even then, it's only good on a niche amount of mons who can't either damage significantly otherwise (ex. Shuckle), or need to trap some easy target for boosting and the like.
Boosting Shell Smash isn't really an option due to the defense drops. You could literally only trap setup on mons with no attacks, which then have 4 other debilitating moves to screw you over with.
Cloyster is not a viable user of Clamp, even if it were to go full 252 HP/Def investment, and with Shell Smash, is a greatly wasted opportunity. Anytime you have a turn to Clamp and survive, you could have Shell Smashed and presented a far more dangerous threat.
