Ooh, this is a really interesting topic for me, because I spent a long time thinking about my stats, and I have quite a few of them.
Sorry if I said something offensive, I’m just trying to get my point across. 
Stat bars exist to keep track of the choices you do that are of the same kind. So yes, if you want the game to know you’re a good liar, you have to lie. Otherwise, how would the game know that you’re good at it? You can’t just say you’re good at it and then not practice it. That’s telling, not showing.
I’m not really fond of choices that’re basically, “What’s your best, good, and worst stat?” I think it would be better if you determine what “stat” you’re best at through choices, one by one. Say, this choice determines your speed. Then the next one, strength. And not, “Do you dodge, or do you block?” That implies that you can’t be both strong and fast.
But, “Wouldn’t the player just pick all the options that increase the stats?” That’s a fair point. I guess you could limit the stat gains for the other stats. It’s also a way out of the four-point trap (choosing from the same four skills over and over) without having extra stats. That way, you explore the weaknesses of the character, and not just everything that happens be a success because you picked your best stat. Maybe create situations where all stats can be tested, so there are varying amounts of success and failure. There wouldn’t be a “best” stat build.
What I’m trying to do with my WIP instead is to make them into opposed personality stats, while keeping a few “attribute” stats like STR, that wouldn’t make sense to be opposing. I like personality stats because they can also serve as “flavor stats”. You can’t exactly tell if a person is strong or weak in a normal conversation.
The apparent problem is, there’s no incentive to stay in the middle. But, by making them personality stats instead of abilities, I’m automatically including a downside.
In my opinion, a “lying” skill works differently than being “deceitful”. A high Lying stat just means you’re good at it. But being deceitful can be seen as both positive and negative. There’s no negative to a high Lying skill, (not counting the consequences).
So, I think by making both sides of the opposed stats “neutral” or both having good and bad effects depending on the situation, you can avoid that problem. You can min-max that stat, sure, but there’s also consequences to it. You can stay at the middle and not succeed very much, but you are also in less “risk”.
I think this is what constitutes as a great opposing stat.
In this case, being too “honest” can make people like you more, as well as have some of them try to take advantage of that, or may think that you’re too blunt.
I have 10 “personality” stats I grouped into personality, thoughts, and actions. I plan not to gate any options or “actions” (although I think how the MC executes the action can also be influenced by the stats), but I’ll have your personality stat determine what your “reactions” are. I think that’s a happy compromise to the “roleplay” argument.
I still have “ability/attribute” stats for things that don’t work exactly that way (like strength). Brutality vs. Finesse like in Choice of the Dragon could work, but I think this is more about how exactly that approach works for your gameplay and narrative.
I haven’t really tested this approach yet, but the way I see it, it fits my story. I’m pretty sure it won’t work for everyone, and that it has both pros and cons to it.
@Tiavals I like your approach, but unfortunately that doesn’t work well in my story where I consider physical stats as secondary since the MC is a child in the modern world. So I think personality stats fits better for me.
I guess it’s how you use the stats that is important, NOT the type of stats you have. They exist for different reasons.
TL;DR of my opinions:
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Stats should track your choices (how you act or how good/bad you are at something), not what you are good at.
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Both sides of opposed stats can have both positive and negative effects. Not just positive ones. Preferring one stat over the other carries consequences as well. Staying in the middle is “low risk, low reward”, but gives a 3rd option.
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Attributes/skills have their place, as well as True/False variables that wouldn’t make sense to track. Depends on the story.
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Don’t gate actions according to personalities (choices), but how the MC reacts to something should be determined by personality (narrative). Depends on the kind of personality if it should be opposed stats or a true/false variable.
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Personality stats are more engaging. Dialogue and narrative that doesn’t change make the MC sound bland and the same whatever your choices are. Depends on the story/POV/how much work you want to do, I guess.
I hope that made sense.
This is just my own opinion and personal philosophy.