Why was Volcarona given 52 Speed?

Question

I chose my Volcs moveset to be

Roost
Fire Blast
Giga Drain
Psychic

And then smogon suggested a spread of
204 HP / 252 SpA / 52 Spe with a Modest Nature.

Why? What benefits do 52 Speed Evs bring over a standard 252 HP / 4 Def / 252 SpA?

Comments

Yeah, it's a strange investment. Usually a number like that would be supposed to hit a speed benchmark of some sort, but there are none that jump out to me.
Smogon's stats show this distribution isn't a popular one, so you can safely ignore it I think.

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That one is an old moveset from the gen 5 meta.

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Oh ok, so it may have kept it in storage?

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What format?

Answer 1

Volcarona with 52 Speed results in 249 speed. Checking common threats in B2W2's meta, I couldn't on earth think of a purpose for 52 speed since the investment doesn't pass the 249 to outspeed 204 Gyarados or 124+ Dragonite, while 32 EVs on Volcarona would've been enough to outspeed max speed Tyranitar, who sits at 243. This was probably meant to pass 373 speed at +1, namely to outspeed these threats:

373 / Gyarados / 81 / Neutral / 204 / +1
373 / Dragonite / 80 / +Spe / 124 / +1
373 / Heatran / 77 / Neutral / 236 / +1
372 / Alakazam, Dugtrio / 120 / +Spe / 252 / 0
364 / Tyranitar / 61 / +Spe / 252 / +1
361 / Starmie, Azelf, Raikou / 115 / +Spe / 252 / 0
358 / Magnezone / 60 / +Spe / 252 (30 IVs) / +1
353 / Tornadus / 111 / +Spe / 252 / 0
350 / Latios, Gengar, Latias, Froslass, Espeon / 110 / +Spe / 252 / 0
346 / Keldeo, Terrakion, Virizion, Cobalion, Infernape / 108 / +Spe / 252 / 0

Checking USUM tiers, 373 isn't a benchmark aside from outspeeding max speed Alakazam, and 249 only ties with 252 neutral Mega Heracross, Mega Scizor, and Tapu Bulu, while 249 leaves it vulnerable to another benchmark; max speed Magearna and Pelipper, combined with a myriad of other Pokemon additions.

So yeah, for the life of me, I can't figure out the reason for this. That's a super bizarre investment.