Tevatron Run 2 results on the inclusive jet cross section
(MidPoint and K_T algorithm) and the b-jet and bb-bar-jet cross section
(MidPoint algorithm) are presented and compared with theory.  The CDF b-jet
b-bar-jet Delta phi distribution is compared with theory and with the D0
jet#1-jet#2 Delta phi distribution.  The understanding and modeling of the
"underlying event" in Run 2 at the Tevatron is reviewed and new CDF results
are presented.