[quote=Spacemarine9]or you could get 5CP an action on a success and 3CP on a fail by grinding almost impossible challenges.
Sure it’s not Optimal for Lootings but if all you’re looking for is quick stat ups it’s the best way[/quote]
Second best. High-Risk will generally be better for grinding stats than Almost Impossible.
Both give 3 CP on a failure. High-Risk gives 4 CP on a success; Almost Impossible gives 5.
If we assume that Almost Impossible has a 10% chance of success, and the higher-probability High-Risk has a 30% chance, then you’re going to be succeeding three times as often with the latter, yielding an average of 3.3 CPs/action vs. 3.2 with the former. Three times as many successes also means the loot will be better, though still paltry.
The problem with risky challenges is, of course, menace, hence this discussion.
If we assume you reduce menace at a rate of 4 CPs/action, normal storylets top out at an effective 2.81 CPs/action when you take menace reduction into account. (Second chances don’t matter here: succeeding on a second chance doesn’t give you the bonus CPs and assuming 3 SCs/action, you end up burning through too many of them to be worthwhile for CP/action purposes.)
True, we’re not talking all that substantial a difference (an extra ~27 actions spent to reduce menaces from ~152 actions of grinding 10 levels of stats), but it’s there.
For those who don’t have easy means of reducing menace, however, it can be more important. If you reduce menace at a 2 CPs/action rate, for example, normal storylets top out at an effective average of 2.44 CPs/action, as you’re spending an extra ~53 actions to reduce menaces from your ~152 actions worth of stat-grinding.
And, of course, this is all in the context of grinding exclusively for stat CPs, without caring about the loot, which is somewhat of a niche case.