Such as reliability, power, firepower, simplicity, capability of being used by others (such as ones family), ease of concealment, use under adverse circumstances (pressing muzzle into adversary, inside pocket, retention position, limp twisted, etc.)
Most of that gets worked out in realistic practice.
In the majority of factors mentioned the J framed revolver, like the Centinnial, excels.
I shoot 642's, with "carry" power ammo, a couple of times a month. About the only thing they "might" excel at, is the contact firing, and inside the pocket thing, both of which I think tend to be over blown by the revolver fans. Most of what Ive found otherwise, has been the small revolvers are not the winner when it comes to "overall".
The contact issue "can" be an issue for the autos, but not always. Many autos will still fire, even with muzzle contact. If you were to run into it, a slight pull back on the gun instantly eliminates it. Not to mention, there are techniques to deal with it, although Im not a fan, as they normally render the gun a single shot.
The pocket thing also is often touted, but in reality, it too isnt really a sure thing, either way. Ive tried it with both revolvers and autos, and both have fired, and both have not. Hammerless revolvers do have an edge there, but the autos I tried it with, fired repeatedly more than they didnt.
How many people do you know, that actually practice shooting that way anyway? Ive only done it a couple of times in over 50 years. Id be will to bet, most have never done it.
The other big issue I have with the pocket thing is, if I see trouble coming, I dont to get caught with a hand stuffed in my pocket. If I somehow dont see it coming, Im not going to waste any time and try and get my hand in there anyway.