I'm not going to dispute this information at all. I agree with it. What I disagree with is the idea that the '50/50' hit rate creates that sweet spot. In fact, given the damage presented by monsters according to all sources, a 50/50 attack rate would -not- present that sweet spot, and cannot.
Just because monster damage is out of whack does not indicate anything.
The sweet spot is about fun, not about monster damage.
If monster damage is too low even without adjusting the math and at the same time, PCs have an easy time getting hit, it means that the sweet spot should be pushed closer to 50/50 for the enjoyment of the players and that the monster damage should be increased.
If monster hit points is too high even without adjusting the math and at the same time, PCs have a hard time of hitting, it means that the sweet spot should be pushed closer to 50/50 for the enjoyment of the players and that the monster hit points might not need to be decreased (because PCs are hitting easier).
It does not mean "screw the players". They are going to get the "have to roll a 17 to hit" sweet spot that we give them.
That POV is just plain assine. WotC would lose market share with that POV and therefore, it is obvious why they added the Expertise feat. To fix the math and not tick off their players.
I fully agree with the 'sweet spot' theory, and the math shows it cannot happen with a solid 50/50 attack rate. The mistake is thinking that the hit rate must remain constant over all levels. That is simply -not true- and cannot be true when player resources are constantly improving.
What math would that be? I haven't seen any math that illustrates that. I have seen claims that since PCs get more powers, the math should be worse.
But, how is that sweet spot? How is missing on a 16 fun in any way, shape or form?
Nobody said anything about it remaining constant. We are talking about it not going crazy though. +7 is crazy. +2, no big deal.
You claimed that there was no evidence.
Let’s review what evidence we have:
Fact: High level combat tends to take 15 to 20 rounds.
Fact: WotC in the pre-release explicitly state that they do not want long encounters because it is outside the sweet spot.
Fact: Having a -4 to hit or having the monster have a +4 to +7 to hit lengthens the encounter by definition.
Number of rounds of combat was explicitly listed as part of the sweet spot. It doesn’t make sense that +/- 8 rounds of combat is the sweet spot at low level and 15+ rounds of combat is the sweet spot at high level.
This is solid evidence of being out of the sweet spot that you ignore. From your position, 20 rounds encounter ARE the sweet spot. Sorry, but that’s just silly.
Fact: Many if not most players do not have fun with the PC getting hit on a 2.
Fact: WotC added two new feats that can change that so that the PC gets hit on a 6 to 8.
If getting hit on a 2 were in the sweet spot, WotC should not have added these feats. It would just be part of the game. There would have been no need, but evidently WotC saw a need. Not only did they see a need, but they saw a need for +6 more to defenses and +3 more to attacks. +3 and +6 are HUGE mods in a D20 game system.
Why add such imbalanced and large bonuses if there were no need? Doing so without a need would be tantamount to blowing balance out the window. +6??? That’s so huge and unbalancing if the game were balanced to begin with.
Fact: WotC adjusted the heavy armor tables in Adventurer’s Vault and PHB II.
Fact: The math indicates that there is a problem if one does not make an adjustment.
It’s apparent that WotC is making changing to fix math problems. Here is one example. Why would we conclude that the feat changes are not another when what they do is significantly adjust the math by definition if used.
If they wanted 50/50, then monster damage would scale with healing power (it doesn't), or at very least, with party hp (it doesn't).
One cannot assume this. The general consensus for people who have played high level is that monster damage at high levels is low, monster hit points at high level are high, etc. We cannot make any assumptions about how monster damage should scale with healing power when all indications are that monster damage is screwed up.
Claiming that this is so is the equivalent of claiming that that sweet spot is correct for high level and we have high level players that disagree with this. 20 round high level encounters shouts disagreement with this.
The bottom line appears to be that they screwed up high level and are now fixing it. Just like they screwed up heavy armor paragon level AC and fixed it.
Summary: The 'Sweet Spot' isn't referring to having the same to-hit rate for monsters and players, and insinuating that it does when the very same math uses the term 'math and complexity.' Complexity. That implies that it's not reduced to one number.
Obviously there are many factors.
But, it’s also obvious that the math is one of those. They fixed the math for Heavy Armor at Paragon level. Obviously if the math were not a factor, they would not have done that.
They stated that both math and complexity are important. That means not just complexity as you are implying.
And, their very actions (adding the feats and fixing the heavy armor) indicate that a major adjustment is needed.
Not that they wanted PCs that already have good defenses to use two feats and rarely get hit on a given NAD. That's nonsensical.
As a wise man once said: "If it looks like a horse and smells like a horse and sounds like a horse, I'm not going to go looking for a zebra".
Occam's Razor. We take the simplest explanation that fits the evidence, not the complex one that satisfies our personal POV.