Hypothetically, there is a limit to the amount of skill you could have in toribash, or with your example, Jaker and his entries in the Book of Records. There is a limit on how fast you can, say, split yourself in half, or break every joint off yourself, or uke. However there is possibly no limit on how far you can, for example, throw something, or fall from. We could push, and push the limits as much as we want, but there would probably be no end to how far we could go. We can only guess where the limit is. For time based things, we are very close to getting things optimised, if not, we are at the limit. For everything else, we are not quite sure where the limit is, but I personally like to think we're somewhat close, but in reality, we are probably far from the limit.