When I spoke to pitchers after an outing, I would let them know that it was not so much the pitch they selected that was the problem. It had much more to do with the location of the pitch. For an example of this, let’s say a pitcher threw a curve ball to the 8th hitter with a 3-2 count and nobody on base which resulted in a walk. First, I would say that if he had thrown it for a strike, it probably would have worked and we wouldn't be having this conversation. Second, I would try to use some stats to make the case that another pitch may have been more effective and involve less risk. Say a pitcher has thrown a fastball for a strike 75% of the time and has thrown a curveball for a strike 55% of the time. A curve ball in a 3-2 count could be a great pitch but only if it’s a strike. The numbers clearly indicate that a fastball would be less risky, especially in that situation. Of course, every situation is different. With runners on 2nd and 3rd, 2 outs, and the best hitter at the plate, the low percentage curve ball would be a great pitch in that situation with the base open at 1st.
After the debriefing, the pitcher then has two options if faced with the original situation again. Throw a higher percentage fastball or work to bring his curve ball numbers up higher so that it could be a good pitch to throw. Occasionally the latter does happen. A former roommate of mine once threw fastballs for strikes in the mid-60% range and actually threw his curveball in the mid-70% range. Not surprisingly, batters saw a lot of curve balls in traditional fastball counts. By the way, he was 10-0 in that minor league season.
The point is, there should be no blanket statement that a particular pitch is the “wrong” pitch to throw in a given situation. Any pitch can be effective if the pitcher puts it where he wants to. The key is to show pitchers, based on their own individual strengths and weaknesses, that there may have been a better pitch for them to throw in that situation.