Wily Peralta? Wow Sorry, speechless for a bit. Now that I’ve had a chance to recover let me just say Nelson in 15 and 16 young pitcher with good stuff and no command. His mechanical adjustment made in early 17 improved his curveball and command of all his pitches, hence ace like pitcher all of 17 til injury. He figured it out, like ALL good pitchers eventually do. If Jimmy not injured I’d say 90+% 2018 season similar to 2017 season. It isn't about comparing their skill levels. It is the concept that one can figure things out and take steps back in the future. Wily Peralta was promising himself and showed flashes of potential through his early years of struggle. You can attribute Nelson's success to a mechanical change etc., but that doesn't really change the fact he can regress. If mechanical changes were so magical I would think Wade Miley could have secured a nice multi year deal. I am not sure how many pitchers who debut at 25+ years old, are average for a good chunk of time, and suddenly vault into the Top 10 analytically as pitchers...but it seems pretty unlikely. At the end of the day Nelson is a baseball player and more importantly a pitcher. Where career years are common and regression also very common. Whether a #5 pitcher or a #1 pitcher one is likely to have major outlier seasons good and bad. It is especially concerning when a pitcher depends on command as you say to be elite vs. average. He could lose that overnight...he has zero track record with good commond outside of 2017. Is it crazy to think Nelson went from average to having a career year and would have settled in as a really good #3 or a low end #2?