Let's see some calcs:
- CB Terrakion's Stone Edge vs 248 HP / 188 Def+ Gliscor: 44.47 - 52.69%, 35.55% chance to 2HKO after SR
- Same attack vs 248 HP / 252 Def+ Gliscor: 42.77 - 50.42%, 6.64% chance to 2HKO after SR
- +2 Terrakion's Rock Gem Stone Edge vs 248 HP / 188 Def+ Gliscor: 88.66 - 104.81%, 31.25% chance to OHKO
- Same attack vs 248 HP / 252 Def+ Gliscor: 84.98 - 100.28%, 6.25% chance to OHKO
I don't know if there is anything else important that Gliscor can take with max Defense, but these calcs are more than enough reason. Gliscor with max Defense will almost always counter Terrakion, where speedy Gliscor has realistical chances to lose. I don't get why a defensive Pokemon should spend 18 valuable Defense points (19 if you count for the + nature) to outspeed a threat that doesn't exist, Jolly Ttar. Not to mention Breloom. You outspeed Breloom, ok so? Gliscor is a shitty answer to Technician Breloom anyway, actually fares better against SubPunch if it is slower, so that it can Roost without getting murdered by Seed Bomb / Focus Punch, and finally beats SubSeed sets no matter what if running Taunt. So tell me, what is the reason for the Speed evs? To outspeed Magnezone? A poke that can murder you on the switch with HP Ice, and is walled by a ton of pokes anyway? A poke that will never switch into you, or try to revenge kill you without a Scarf?
So yeah 248 HP / 252+ Def is the way to go guys. Oh and U-turn should really get a slash. Almost all defensive pokes that get U-turn/Volt Switch and don't suffer from huge 4mss have them in their sets, so why not Gliscor? Or at least an AC mention... Always talking about the Defensive set.
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