Try and learn to throw a putter and neutral mid range further for awhile. Learn to make the disc bend different directions. Hyzer(left), anhyzers (right) and straight shots. I'd recommend a wizard, aviar (kc, jk, yeti, dx, xt) nova, dart and other under stable to stable for putters. For mid range I'd shoot for a comet, mako, mako3, stingray, panther, shark, tursus and other under stable/ neutral/ slightly stable mid range.
Learn to throw those good and return to that roadrunner it'll fly like the numbers suggest better. The roadrunner is a high speed driver. The first number is at what speed it needs to fly to make the other numbers correct. 9/4/-4/1. 9 doesn't sound that fast but when you say it's a straight disc if you look it says it's -4 which means the roadrunner is supposed to turn right (for right hand backhand throw) which is called high speed turn. When the disc is thrown flat and at the 9 speed (whatever that is lol) it'll turn to the right -4 and come back +1.
A disc like a mako with 0/0 for high speed turn and fade is made for a straight shot. Whatever that disc does will show you exactly what your doing to it. It'll show you when you turn your wrist over(it'll go right), torque it (go right/cut roll/ roller), not enough speed (hyzer/ go left), wrist roll under (it'll hyzer/ go left a lot). I recommend learning to throw flat and learn a sidearm at the same time. An you'll be a high intermediate player in no time flat
