Why is Hyper Beam rated as a better defensive move for Blissey than Psychic?
Looking at sims of perfect L40 Machamp vs Blissey, Psychic hurts Machamp much more both with realistic dodging and no dodging. With perfect dodging, Hyper Beam deals a whopping 1 more damage over the course of the battle. This looks to me like a very clear difference against the optimal Blissey counter, especially with perfect dodging against Psychic being quite hard (FB Mewtwo exists, sure, but Machamp is faster and more available).
I feel that the distinction of the worst and second worst move is an important one for the players who are low on CTMs and need to know when they can use one for a guaranteed improvement. And based on the sims I'd argue that Hyper Beam is the worst move that should always be TM'd.
Answers
Psychic doesn't threaten anything but machamp, and isn't /that/ hard to dodge if you're paying attention. Hyperbeam does much more damage otherwise (Mewtwo comes to mind) and isn't dodged as much in practice as in theory. At the end of the day, Blissey is so obese that even her worst moveset outclasses everything else, so save your tm's.
Poke2battler has zen/hyperbeam over even pound/dazzling, fwiw.
https://www.pokebattler.com/rankings/defenders/levels/40/attackers/levels/40/strategies/DEFENSE_RANDOM_MC/DODGE_SPECIALS/ranks/1?sort=OVERALL&weatherCondition=NO_WEATHER&dodgeStrategy=DODGE_REACTION_TIME2#rank1
"Blissey is so obese that even her worst moveset outclasses everything else." -- There goes that old cliche again. Completely untrue. "Time to win" in simulations is not what makes a good defender. Good defenders have unpredictable moves that can hit for unexpected damage, and/or make you switch attackers. Everyone knows exactly what it takes to beat a P/HB Blissey, and there is no unpredictability about it whatsoever (as opposed to, say, BS Snorlax or DC Dragonite).
I could not disagree more with the idea that Hyper Beam isn't dodged nearly every time in practice. It is pathetically easy to dodge due to how long it takes to wind up. Not that that matters, because sims show that Psychic is better against Machamp nearly always. The argument is mostly about whether Machamp is the attacker we should be planning for and I believe it is, having much better availability than FB Mewtwo and having faster time to win.
Pokebattler creates the overall defender moveset ranking by averaging against the best 30 (IIRC) attackers. Which I don't think creates accurate results, especially when we're talking about the one gym defender that makes people think they want a dedicated specialist for it.
Because the Gamepress ranking is just plain wrong in this case. Psychic has a reasonably good chance to hit, whereas hyper beam has zero chance to hit against a halfway competent L25+ player. This is one of those cases when the rankings seem to rely too much on simulation data, and not enough on real-world practicality.
