Toby and Jonah
\( ERA = 9 \cdot \frac{ER}{IP} \)
\( FIP = 3.15 + \frac{3\cdot BB + 13\cdot HR - 2 \cdot SO}{IP} \)
\( xFIP = 3.15 + \frac{3\cdot BB + 13\cdot FB \cdot lg(\frac{HR}{FB}) - 2 \cdot SO}{IP} \)
\( kwERA = 5.4 - 12 \cdot \frac {K-BB}{TBF} \)