It’s hard not to ride the high of a decisive victory over the Dodgers, even if it is early in the Spring.  Pablo Sandoval went deep, the Giants scored eight runs, and all is right in the world so far in the Cactus League.  I did some math, and if the Giants continue this trend, they won’t lose a single game all season.  More importantly though, it’s Saturday, which means that it’s time to conclude the “What to Expect” series with the fourth and final installment, this time featuring lefty Jonathan Sanchez.

As you were reading this, Jonathan Sanchez walked you and struck you out in the same at-bat.

In what was statistically the best season of his career, 2010 showed us the massive potential of Jonathan Sanchez.  Throwing almost 230 innings (counting the postseason), it was the heaviest work load he’s ever experienced.  Despite some obvious signs of fatigue in his final two postseason starts, for the most part he was everything we expected him to be, plus a little more.  With a typically high K/9 and BB/9 rate, Sanchez surprised no one.  What did come as a bit of a shock though was the 3.07 ERA that many say is due for a heavy regression in 2011.

Statheads will point you in the direction of Sanchez’ low BABIP  (Batting Average on Balls in Play) of .252 as a good indicator of why the ERA is due for a massive spike (leaguer average is right around .290).  Essentially, BABIP is a measurement of how lucky a pitcher based off of how his defense plays behind him.  When it’s high, this usually indicates that a pitcher’s defense failed to get to a lot of playable balls, and denotes that the ERA will be lower as the BABIP regresses to the mean.  When it’s uncommonly low, it’s a good indicator that a player has gotten considerable help from his defense and that his ERA will spike the following season.  Combine that with the fact that Sanchez stranded a career high 79.5% of all baserunners (LOB%), and there’s a good argument to made for regression.

There’s one caveat that should be discussed as well before Sanchez is doomed to fall down the rabbit hole:  BABIP is not a stand-alone statistic.  Rather, it’s dependent on the amount of loud contact a pitcher gives up, which is measured by line drive percentage (LD%).  With the seeing-eye grounder, there’s always a case to be made that a better shortstop would have gotten to the ball.  A pitcher’s defenders behind him can’t be expected to flag down line drives though, and as such it’s up to the pitcher, not the defense, to reduce this likelihood.  With LD%, the rule of thumb is to add .12 to the BABIP in order to tell you what a player’s expected BABIP should have been (xBABIP).  Put simply, it tells us how above or below average a pitcher’s BABIP was in any given season, which in turn tells us how lucky (or unlucky) a player was.  Take a look at Jonathan Sanchez’ last three seasons:

• 2008: 21.4 LD%, .317 BABIP, .334 xBABIP, 67.5 LOB%
• 2009: 16.2 LD%, .276 BABIP, .282 xBABIP, 72.6 LOB%
• 2010: 14.8 LD%, .252 BABIP, .268 xBABIP, 79.5 LOB%

In each season we see a drop in both line drives and batting average on balls in play.  Typically if there’s a difference of about .10-.15 between the BABIP and xBABIP, there’s a good chance that a massive regression isn’t in the cards.  What this three-year progression shows us is that even with the career high strand rate, Sanchez is learning how to reduce loud contact.  In every season he’s reduced his line drive percentage, there’s been a marked increase in his strand rate (LOB%), which tells us that his leaving runners all over the place is more a product of making better pitchers with men on than sheer luck.

Keeping all this in mind, there’s a strong case to be made that any regression Sanchez experiences in the ERA department in 2011 will be minimal.  I have my doubts that he’ll throw up another 3.07 ERA, but a 3.20-3.30 earned run average seems completely reasonable based on the last three seasons.  Taking into account that as a strikeout pitcher Sanchez doesn’t need to rely on his defense as much, the low BABIP isn’t too much of a reason for concern going into this season.

With Bruce Bochy pegging him as the number two starter to begin the season, Sanchez is being counted on to pitch between two star-quality righties (Lincecum/Cain).  There’s not a whole of an argument to be made for Zito being the 2nd best starter on a what’s become a very good staff, and the Giants are trying to limit Bumgarner’s innings, so the 28 year-old lefty is being asked to step into a role he’s never been before.  If he’s anything like the pitcher he was in 2010, I see no reason why he repeat his past successes.

LD%, BABIP, and LOB% provided courtesy of Fan Graphs