sakadachi shite mo
Even if I stand on my hands
No matter how hard I try, (I can’t do …); it is nearly impossible to do …
The expression is usually followed by a negative potential form; the allusion is that even if you make as much effort as required to stand on your hands, you’re unlikely to succeed. It’s often used when you believe that you can never beat/surpass someone.
No matter how hard I try, I can never beat him in Smash Bros.