Aaron Cook: Human Batting Tee

When Aaron Cook's pitching, Boston's backstops might as well take the night off. The 33-year-old righty has always put the ball in play often, striking out just 3.7 batters per nine innings and walking 2.7 during his career, but he has taken his human batting tee act to ridiculous heights in 2012.

Cook carries a three-to-three K-to-BB ratio in 36 innings pitched into his start tonight against the Yankees. That's 0.75 strikeouts and walks apiece per nine innings. According to Baseball-Reference, Cook is the first pitcher since the end of the Dead Ball Era to record less than one walk and whiff per nine frames while throwing at least 30 frames in a season. The only other two pitchers  in MLB history to pull it off are Jake Northrop (1918 Boston Braves) and Slim Sallee (1919 Cincinnati Reds).

As always, Cook is taking a sinker-centric approach, with just a smattering of sliders and curves mixed in. Cook has thrown his sinker 83 percent of the time this season, by far the highest clip among starters (Chien-Ming is second at 70 percent). There's no secret here: He's gonna throw a sinker, and it's gonna be low and in the strike zone:

Cook's sinker location in 2012

Cook has thrown about 49 percent of his sinkers low (the MLB average for starters is 41 percent), and 55 percent of those sinkers have been located in the strike zone (51 percent average). It should come as no surprise, then, that Cook's sinker is a bat magnet:

Hitters' contact rate by location vs. Cook's sinker

Cook's sinker has a 5.3 percent miss rate, tied with the Yankees' Freddy Garcia for lowest among pitchers who have thrown at least 100 sinkers this season. Using the sinker so often, Cook is in a class of his own in terms of opponent contact. His MLB-low miss rate is almost half that of his next closest "competitor," Jeff Suppan:

Lowest miss rate among starting pitchers (minimum 400 pitches thrown)

Pitcher	Miss Pct.
Aaron Cook	5.6%
Jeff Suppan	10.7%
Bartolo Colon	11.1%
Henderson Alvarez	11.5%
Chris Volstad	12.1%
Patrick Corbin	12.3%
Kevin Correia	12.8%
Nick Blackburn	13.5%
Tommy Hunter	13.9%
Derek Lowe	14.3%

Cook's lack of whiffs mean that the catcher is obsolete nearly 60 percent of the time that he throws a pitch:

Highest percentage of pitches put in play among starters (Min. 400 pitches)

Pitcher	In Play Pct.
Aaron Cook	59.9%
Jeff Suppan	54.7%
Jeanmar Gomez	53.0%
Dallas Keuchel	52.8%
Nick Blackburn	52.5%
Derek Lowe	51.9%
Henderson Alvarez	51.7%
P. J. Walters	51.3%
Bartolo Colon	51.2%
Jeremy Guthrie	51.1%

The Human Batting Tee has actually been pretty successful so far (3.50 ERA), but he has benefitted from a .222 batting average on balls in play and his fielding independent ERA is over a run higher (4.59). Can he keep this up? I don't know. Probably not. But right now, Salty and Shoppach have the best seat in the house to see baseball's biggest oddity.

Sox Turn to Scrap Heap for Starters

Boston's rotation was a major weakness in 2011. Jon Lester and Josh Beckett had quality years, but a back injury cut Clay Buchholz's season short and starts by other Sox pitchers were short and  brutal. Boston placed ninth in the American League in starter ERA, 11th in Fielding Independent Pitching and second-to-last in innings pitched.

But, rather than making a big-ticket free agent or trade acquisition to compete in the arms race with the Yankees and Rays, the Red Sox are hoping for a return to health for Buchholz, a successful transition from the 'pen for Daniel Bard and perhaps Alfredo Aceves, and a bounce back year for at least one of a trio of recently-signed scrapheap starters. Here's a look at new Red Sox reclamation projects Aaron Cook, Carlos Silva and Vicente Padilla.

Aaron Cook

Cook, 33 next month, used an earth-scorching sinker and exquisite control to emerge as a quality starter for the Colorado Rockies. From 2006-2009, the righty overcame a sub-four-per-nine strikeout rate to post a 116 ERA+ and compile nearly 10 Wins Above Replacement. Since then, however, Cook has dealt with shoulder, leg and finger injuries, most recently missing three months in 2011 after breaking his ring finger in a door. His ERA+ since 2010 is just 83, and he has been worth less than one WAR in over 220 innings.

Cook was effective when he complemented his ground assault with few walks (2.3 BB/9 from 2006-2009), but he hasn't been near as sharp over the past two years (3.6 BB/9).  You might think he's missing out of the zone more often with his sinker, and you'd be right. Cook's percentage of in-zone sinkers has fallen in recent years, and hitters are chasing fewer of those off-the-plate pitches to boot:

Player	2008-09 Zone%	2008-09 Chase%	2010-2011 Zone%	2010-11 Chase%
Cook	52	29	50	25
League Avg.	46	29	51	27

Put another way, his zone percentage with the sinker was 13 percent above the league average in 2008-09 and two percent below average in 2010-11. Cook is still getting grounders with his sinker, but the extra walks and hitter's counts in general have made the pitch much less effective (batters slugged .417 against Cook's sinker in 2008-09, and .454 the past two years). If Cook doesn't start being more precise with his sinker, the door could slam shut on his career.

Carlos Silva

Owner of the lowest walk rate among active starting pitchers, Silva had a few nice seasons with the Twins in the mid-aughts. But the beefy righty and the four-year, $48 million deal he signed with the Mariners had become a punch line by the time he was shipped to the Cubs after the 2009 season for Milton Bradley in a dead money challenge trade.

Shockingly, Silva was actually pretty good in Chicago. He had a 100 ERA+ in 113 innings, striking out far more batters than ever before (6.4 K/9) while still being stingy with the walks (1.9 BB/9). Silva radically changed his approach: while he threw a fastball nearly 70% of the time in 2008 and 2009, he went to his not-so-hopping heater about 57% with the Cubs, mixing in more changeups and sliders. Check out the difference in his opponent contact rate in 2008-09 and then 2010. Keep an eye on the low-and-away area for righty batters, where most of Silva's stuff was located:

Opponent contact rate by pitch location vs. Silva, 2008-09Opponent contact rate by pitch location vs. Silva, 2010Hitters swung and missed at Silva's pitches a paltry 11 percent of the time in 2008-09, but that increased to a little over 17 percent in 2010.

Unfortunately, Silva's comeback was curtailed by a heart condition that required surgery in August. Chicago cut him on the eve of the 2011 season, and Silva didn't throw a big league pitch while suffering from shoulder soreness and pitching scarcely in the Yankees' farm system (New York also released him in July). If the 32-year-old is healthy (an admittedly large if), Silva at least keeps the Sox from praying that Andrew Miller can avoid hitting the backstop in the event that the club needs a spot-starter.

Vicente Padilla

Padilla pitched just 8.2 innings out of the bullpen for the Dodgers last year and has dealt with a litany of ailments in recent years, including surgeries for a chronic problem with a bulging disc in his neck and a trapped nerve in his forearm in 2011. When on the mound in 2009 and 2010, Padilla was a decent, if unspectacular rotation option (99 ERA+ in 242.1 innings pitched).

If Padilla does end up on the mound for the Sox in 2012, new manager Bobby Valentine should try to use him on days when Boston is facing a lineup slanted to the right side. With a low three-quarters arm slot and little in the way of secondary stuff, Padilla is susceptible to lefty hitters. Walks are Padilla's biggest bugaboo against lefties:

Padilla's splits, 2009-2011

	PA	AVG	OBP	SLUG	K%	BB%	HR%
Vs Left	565	.259	.339	.419	17.7%	9.9%	3.6%
Vs Right	561	.246	.299	.378	18.4%	5.5%	2.9%

There's no harm in the Red Sox bringing in low-cost retreads like Cook, Silva and Padilla to add rotation depth. It's possible that one or two of the trio comes to camp mended and performs well enough to help out in 2012. Bartolo Colon and Freddy Garcia did the trick for the Yankees last year. But the absolute best-case scenario for any of the three is adequacy -- there's no plausible scenario in which one of these guys has a huge season.

Given that the Bombers and the Rays have both have top-tier talent and 7-8 legitimate rotation options, I find it hard to believe that Boston won't kick the tires on a higher-upside option like Roy Oswalt (seeking a one-year deal), luxury tax concerns aside. A pitcher capable of three-plus WAR like Oswalt or settling for Cook, Silva or Padilla could be the difference between a playoff spot and another cold, acrimonious winter for Red Sox Nation.