Francisco Liriano and the Unhittable Slider

We all know it's good.  But let's take a  moment to talk about how good.

Digusting.  Filthy.  Ridiculous.  Unhittable.  There are quite a few flattering terms that people have used over the years to describe Francisco Liriano's slider.  It's his strikeout pitch, and if you're stepping into the batter's box, no matter who you are you don't want to see it.  You're hoping against hope that, for whatever reason, the baseball gods have mercy on you and that Joe Mauer just puts down the ol' number one.

This season, Liriano has gone with the slider 32% of the time.  That's more than anybody else in Minnesota except Jesse Crain, and the only two starting pitchers (minimum 500 sliders thrown) who throw it more often are Ervin Santana and Bud Norris.

And neither of them are as good at it as Liriano.

According to FanGraphs Liriano's slider has been 22.4 runs above average this season, and impressive mark, leaving second place (Randy Wells, 15.4) in the dust.

Who's been dealing the best sliders in 2010?  Santana and Norris have both held opponents to a sub - .600 OPS on the pitch, but neither even crack the top ten.  Wells is seventh.  Here at the best five...and look who's at the top.

Just so it's clear how terrible that is, a lineup with an on-base percentage of .221 and a slugging percentage of .191 would score about 0.6 runs per game.  And as far as OBP on a pitch, I have to assume Inside Edge is including sliders on ball four.

Marmol is the only relief pitcher breaking the top five, but the fact that he can throw it so consistently and still be so effective is a sign of exactly how electric his slider is.  Liriano's slider, like that of any good starter, isn't a bottomless well.  It's deployed strategically, in two-strike situations or to occasionally keep hitters off-balance earlier in the count.  And Liriano is better at doing that than anybody.

A large part of that is because he makes people miss.  Going back to a minimum of 500 sliders thrown this season, nobody has struck out batters at a higher rate off the slider than Liriano's 53%.

Overall, hitters are whiffing on 23.2% of Liriano's slider.  That's better than any of the starters we've mentioned so far:  Jackson's ratio is impressive (22.6%),  but Norris (18.9%), Santana (17.9%), Wells (17.3%), Sanchez (13.3%) and Carmona (8.7%) don't hold a candle.

The closest peer to Liriano in terms of slider wickedness this season is Brandon Morrow.  You don't hear too much of him, partially because he plays for Toronto and partially because this is the first year where he's really been starting full time, but his whiff percentage actually trumps Cisco's at 27.3%.  He's thrown 330 fewer sliders than Liriano this season and hitters are still having more success off of it, but with that rate of swings and misses there's no doubt that he's nasty.

For most of the season we've heard the talk of the 2010 Francisco Liriano being almost as ridiculous as the 2006 version, and while the slider no longer rests in the upper 80s, as far as measures of effectiveness go it's an apt comparison.  And the poor Kansas City Royals get to experience it first-hand in just a few hours.