|Luck’s Impact on Four Players||| Print ||
Written by Lewie Pollis (Contact & Archive) on March 04, 2011
One of the most incredible innovations of the sabermetric movement is the quantification of luck. While it's impossible to truly isolate players' talent from luck in their performance, some of these newfangled statistics can give us a pretty good idea of which players are the beneficiaries of good luck, which are struggling through no fault of their own, and which are producing at about the level they should be.
As we look ahead to 2011, I've listed some of the players who experienced some of the most dramatic streaks of luck -- both good and bad -- in 2010. But first, here's an explanation of some of the statistics you should know.
BABIP - Batting Average on Balls in Play. Also known as "hit rate," BABIP is exactly what it sounds like -- the proportion of batted balls a batter hits or a pitcher allows somewhere in the confines of the diamond that fall for hits. The league average is right around .300, and year-to-year variations are almost always due to luck
LOB% - Left on Base Percentage. Also known as "strand rate," the meaning of LOB% is also easy to understand: the proportion of baserunners a pitcher allows that don't score. Most pitchers' strand rates hover right around 72%; a good pitcher can maintain a higher LOB% (the more outs a pitcher gets, the fewer chances the baserunners have to score), but most fluctuations are due to luck.
HR/FB - Home Run Rate. This one also is pretty intuitive. HR/FB is the proportion of fly balls a batter hits or a pitcher allows that end up clearing the fence. For pitchers, this is often seen as a product of luck. Like LOB%, some pitchers have demonstrated an ability to consistently post high or low HR/FBs (groundball pitchers tend to have higher marks), but for most pitchers, variations seem to be random chance. Most years, the average home run rate is around 10.6%, but last year that dropped to 9.5%.
xBABIP - Expected Batting Average on Balls in Play. An estimation of what a batter's BABIP should be based on his batted-ball profile and other reliable statistics. Calculated with the use of The Hardball Times' Simple xBABIP Calculator, we can substitute it for a player's actual BABIP to determine his luck-neutral statistics.
A similar, less reliable method can be used to find xBABIP for pitchers by simply using the league-average BABIP values for each batted-ball type.
FIP - Fielding Independent Pitching. An estimation of what a pitcher's ERA would be in a luck-neutral environment, calculated solely based on strikeouts, walks, hit-by-pitches and home runs allowed.
xFIP - Expected Fielding Independent Pitching. The same as FIP, but with home runs allowed replaced with an estimate of how many home runs the pitcher would allow in a luck-neutral environment, calculated by using the pitcher's fly rate and the league-average HR/FB. Based on the idea that a pitcher has no control over whether a fly ball leaves the park.
tERA - True ERA. Like FIP and xFIP, but taking the pitcher's batted-ball profile into account. Based on the idea that a pitcher can control the type of contact he induces, even if he cannot control whether or not the play results in an out.
All three of these ERA estimators are better predictors of future ERA than is past ERA.
Lucky Hitter: Austin Jackson, Detroit Tigers. The Tigers got a lot of flack when they traded Curtis Granderson last winter, but they probably felt pretty good about the deal when Austin Jackson, the prospect they traded for to replace Granderson, finished second in the AL Rookie of the Year voting and made a name for himself as a player to watch for years to come. In his debut season, the 23-year-old hit .293 with 103 runs, 27 steals, and 3.8 WAR.
That he was able to hit for such a high average may seem a bit odd given that Jackson supported his superficially strong contact skills a subpar walk rate (7.0%) and an unsightly 10th-percentile strikeout rate (27.5%). How did he pull it off? Blame his .396 BABIP, the highest in the game.
Jackson is the kind of player who could sustain a high BABIP. His 24.2% line-drive rate was tied for the best in the league last year, and his good speed complements his groundball-hitting ways well. But the idea that he could maintain a hit rate this high is absurd. His .355 xBABIP reflects his impressive batted-ball profile, but .355 is still a long way from .396.
Plug his xBABIP in for his BABIP and, making the simplifying yet generous assumption that every hit he'd lose would be a single, his 2010 slashline falls to .263/.311/.370. With a below-average OBP, he would have fewer chances to steal bases and score runs, which would drag his value down even further. A guy with a .681 OPS isn't a Rookie of the Year candidate. With that kind of production, he'd have trouble just finding a job.
Unlucky Hitter: Carlos Pena, Chicago Cubs. Carlos Pena has been in a steady decline since his 46-homer, 6.2-WAR breakout season with the Tampa Bay Rays in 2007. His slide continued into 2010, when his average dropped to .196 and he managed just 28 homers, 84 RBI and 1.0 WAR. It's hard to believe he found a team willing to give him a $10 million contract this winter.
As a power hitter who strikes out a lot (batters with high whiff rates tend to hit the ball harder), at first glance Pena may seem like a guy who could sustain a high BABIP. But he posted a .250 hit rate in 2009, and he's never maintained a BABIP over .298 for a full season, which makes sense for a flyball hitter with little speed. And so, while Pena's .222 hit rate seems a bit overdramatic, it doesn't seem like a major anomaly.
In actuality, his BABIP was 99 points too low. On the strength of his power, Pena ends up with a .321 xBABIP. Take his 2010 stats and plug his xBABIP in for his BABIP and, assuming that all the hits he'd gain would be singles (and given that his .211 ISO last year was higher than his batting average, it's safe to say a large number of the extra hits would go for extra bases), you get a .258/.377/.479 slashline.
An .856 OPS would still represent a relatively disappointing showing for Pena, but it would put him just behind Ryan Howard (.859) and on par with David Wright, both of whom are doing pretty well for themselves offensively.
Lucky Pitcher: Trevor Cahill, Oakland Athletics. When Trevor Cahill broke into the Major Leagues in 2009, he was expected to rack up the K's. After all, he struck out 10 batters per nine in three years in the minors, which led to his No. 11 ranking on Baseball America's top prospects list before the season. He ended up having a fine year, a 4.63 ERA is a solid showing for a 21-year-old rookie, but his whiff rate dropped by more than 50% to just 4.5 K/9.
Cahill followed that up with a breakout sophomore campaign in which he went 18-8 with a 2.97 ERA. His success corresponded to legitimate improvement: he showed solid control (2.9 BB/9), induced grounders well (56% GB rate), and while his 5.4 K/9 was still mediocre, it was a step in the right direction. And yet, his FIP stands at 4.19, suggesting something fishy.
The key to Cahill's success was his ridiculous .236 BABIP. For some comparison, Jeremy Guthrie, who had the league's second-lowest BABIP, weighed in at .254. The last time a qualifying American League pitcher ended the season with a lower hit rate was Derek Lowe in 2002, with .235.
Cahill's batted-ball profile suggests that he can maintain a good hit rate. But this good? Even assuming his 15% line-drive rate wasn't a fluke, his xBABIP is .279. Forty-three points is a huge difference, especially for someone who lets batters put the ball in play. More hits would mean his 76.5% LOB rate would come down, and his ERA would rise accordingly. Even if he continues to improve as a pitcher in 2011, he'll see a big downturn in his stats.
Unlucky Pitcher: Francisco Liriano, Minnesota Twins. When he went 12-3 with a 2.16 as a rookie in 2006, 22-year-old Francisco Liriano was hailed as one of the best pitchers in the game. That changed when he had to undergo Tommy John surgery after the season. He lost all of the 2007 campaign to his recovery, and went 11-17 with a 5.12 ERA in parts of 2008-9.
Something changed in 2010. Liriano stayed healthy enough to throw nearly 200 innings with a 3.62 ERA. He contributed 6.0 WAR to a team that won its division by six games, meaning he truly carried the Twins to a division title. How could a guy who suddenly had so much success after three years of injuries and ineffectiveness qualify as unlucky?
Check out his peripherals. Liriano struck out more than a batter per inning (9.4 K/9) and posted a 3.5 K/BB ratio. He was fairly fortunate with his 6.3% HR/FB, but with a 53.6% groundball rate, he didn't give opposing batters much of a chance to hit the ball out of the park anyway. If not for his .331 BABIP (his xBABIP was .300, on the nose), you would have seen him mentioned in the AL Cy Young conversations.
What would his ERA have looked like with neutral luck? FIP has Liriano at 2.66 -- better than anyone not named Josh Johnson or Cliff Lee. He gets a slightly smaller (though still substantial) boost from tERA, which pegs him at 2.93. His 3.06 xFIP is the least generous estimator, and yet it still has him more than half a run lower than his ERA. And by the way, his xFIP was the best in the league.