johnsojc wrote:
Is it my imagination or are all those oven response curves identical except for the scaling along the temperature and nutrient axes? It looks like ovens 1, 2, and 3 are just slices taken from the beginning of the response curve for oven 4.
It's your imagination. Each oven does have an individual response curve, and they are different. The differences among the first 3 ovens are clearer at higher cooking times, but you can see them even in the first set at time 20. (Count the bands, for example, which show that some of the curves are steeper than others.) Each oven also has a different set of caps on each setting, beyond which the values remain constant. I cut off the chart data at those caps, which is the main reason for the scaling differences Belford is complaining about. 
oyferder wrote:
Is the goal to have as high pellet nutrient value as possible(is it that which gives us as many pellet points as possible), or is it too high nutrient value that gives us explosions?
In character, FPI refuses to answer any questions about how exploders are produced. But, OOC, you are correct that the exploders occur at the highest levels of nutrient values, so the optimum orange-glow recipe is below the peak of the combined oven response.
I have no idea how the points are determined, except that they aren't simply equivalent to the nutrient value. The points seem to go up until you hit a combined value of around 200, then start going down again until they reach zero at the exploder level. I don't have enough data to tell me if the points just follow a bell curve or if it is skewed somehow. (Though I suspect skewing, where the points fall off on the far side faster than they climbed.)
The steamers occur at the negative values. It is interesting to note that oven 2 is incapable of producing a negative value at any cooking time. (Another example of the difference in the curves for johnsojc.) So the best strategy for steamers is to use low settings on oven 2, such as 5-5-5, forcing the response to zero so it doesn't counteract the others.