Both of them employ lights out closers who can strikeout hitters and pitch more than an inning.
The Mets have Jeurys Familia and the Royals have Wade Davis. After them, the Royals have more reliability in the 7th and 8th inning roles. Kelvin Herrera is a stud who throws hard and has a nasty slider which makes him virtually unhittable. Set-up man Ryan Madson has had a nice comeback year, but blew Game 6 of the ALCS.
The Mets also have a shaky set-up man in Tyler Clippard, who has been shaky since September rolled around. Addison Reed has been up and down in these playoffs but had a nice NLCS. The Mets best reliever outside of Familia in the postseason has clearly been starter Bartolo Colon.