Much like in real estate, when it comes to pitching - location matters. You can have a great slider but it starts outside the zone, hitters are unlikely to chase. High spin fastball? Excellent, but throw it down the middle of the plate and it may leave the park. There is much more to pitching than just having one good pitch. That being said, I was curious so I started doing some research on Angels pitching and looking into the best pitch for each pitcher.
Determining the best pitch was largely based on Swinging Strike (or whiff) rate, out of zone swing percentage, and Fangraphs pitch value.