How do you get the knuckleball in my league pitcher mode?

U have to train curve also, if you're curve gets high enough the pitches you can learn are the P Sinker,P Slider, Knuckle and Gyro these all require G points to train, a easy way to do this if you have lots of G points is buy items in the G Point shop that increase curve hope this helped =) I apologize if this is wrong but to my knowledge this is correct because while training curve for my pitcher a senior informed me I could learn the pitch I hope this helped =)

It varies. In my case, the Power Sinker unlocked first as I hit 500 curve or something like that. After that came the Power Slider at 600 curve. Then came the Knuckleball at 700 curve. And last of all came the Gyroball at 800 curve. Now, all these curve levels apply WITHOUT EQUIPMENT. The fastest possible way to achieve this is by way of completing all the pitcher missions multiple times. Once that's done, buy a crap ton of Mom's Lunchboxes and boost ALL your stats by a large margin. That unlocked all the secret pitches for me in just two seasons, and I am now in my 10th season sitting at 999 for all stats and with the Gyro, Knuckle, P. Sinker, P. Slider, and 5 Super Pitches. This pitcher that I now have is OP as heck, I'll give you that. He can pitch up to 12 innings before getting fatigued (of course that's only if your go overtime and use a bare minimal amount of breaking balls), and even if his pitches don't reach full gauge, they still often tend to land within the strike zone. His fastball tops out at 98 mph, while his P. Sinker and P. Slider both top out at 94 mph. Also, his Knuckle hits a minimum of 65 mph, while his mighty Gyro tops out at a flaming 102 mph. I know, I'm kinda flexing at this point, but it's taken so much time and effort to get him to where he is. In the end, training your pitcher to the max is more than worth it, especially when you decide to insert him into your starting rotation in Season mode