CSS Button No Image Css3Menu.com

Baseball Prospectus home
  
  
Click here to log in Click here for forgotten password Click here to subscribe

<< Previous Article
Collateral Damage: Div... (10/10)
<< Previous Column
Fantasy Article Resident Fantasy Geniu... (10/03)
Next Column >>
Fantasy Article Resident Fantasy Geniu... (10/17)
Next Article >>
Premium Article Playoff Prospectus: Th... (10/10)

October 10, 2011

Resident Fantasy Genius

Can Pitchers Control Their Consistency?

by Derek Carty

the archives are now free.

All Baseball Prospectus Premium and Fantasy articles more than a year old are now free as a thank you to the entire Internet for making our work possible.

Not a subscriber? Get exclusive content like this delivered hot to your inbox every weekday. Click here for more information on Baseball Prospectus subscriptions or use the buttons to the right to subscribe and get instant access to the best baseball content on the web.

Subscribe for $4.95 per month
Recurring subscription - cancel anytime.


a 33% savings over the monthly price!

Purchase a $39.95 gift subscription
a 33% savings over the monthly price!

Already a subscriber? Click here and use the blue login bar to log in.

In my preview of the NLDS between the Brewers and Diamondbacks last week, reader mopup1 posted a comment relating to something I’ve been meaning to look into for a while now.

I'm sure Derek and anyone in a week-week fantasy pool knows this but Gallardo's prone to S*it the bed at times. 6 times this season he's allowed 5 ER or more. His inconsistency is a big issue IMO in a playoff scenario.

Fans and analysts often talk about how a particular pitcher is inconsistent or how another is prone to a dominating or disastrous outing, but I’ve never seen a study looking at whether this sort of consistency (or inconsistency) is a repeatable skill. Surely it happens—as mopup1 said, Gallardo took several beatings this year—but is it something that the pitcher has any control over, or is it merely random luck? You see, for forward-looking purposes (like fantasy baseball), it only really matters if it’s something the pitcher can control. Otherwise, it’s nice to look back on and mention, but it wouldn’t tell us anything about whether the pitcher will be similarly consistent (or inconsistent) in the future.

To study whether start-to-start consistency is a repeatable skill for a pitcher, I’m going to look at several different measures of a pitcher’s performance in a given start:

ERA: Earned Run Average
FIP: Fielding Independent Pitching
Quality Starts (QS): A pitcher is awarded a quality start if he pitches at least six innings and gives up no more than three earned runs
Game Score (BJ GS): A stat invented by Bill James, it includes innings pitched, strikeouts, walks, hits, earned runs, and unearned runs.
Pure Quality Stats (PQS): A stat invented by Baseball HQ, it accounts for innings pitched, strikeouts, K/BB, hits, and home runs
True Quality Starts (TQS): A stat I invented at THT, it’s my stat of choice to measure individual starts since it uses run values (as opposed to the arbitrary weighting of Game Score and PQS) and ignores earned runs, hits, and homers. Instead, it uses strikeouts, walks, and line-drive neutralized ground balls, fly balls, and popups.

The Study
To measure how consistent a pitcher is in terms of each statistic, I’m going to use a statistical tool known as a standard deviation. A standard deviation tells us how closely a group of numbers is clustered together. So if, say, a pitcher’s TQS scores are clustered very closely together, he’ll have a low standard deviation—in other words, he’s been consistent. If his TQS scores are far apart, however, he’ll have a high standard deviation—in other words, he’s been inconsistent.

From here, I’m going to look at all pitchers who started at least 20 games in back-to-back seasons since 2002 and compare their consistency (as measured by standard deviation) between the two years. To do so, I’m going to run a correlation, which measures the relationship between two sets of numbers. The closer to zero, the weaker the relationship; the closer to one, the stronger the relationship.

The Results

Stat

Correlation

TQS

0.070

FIP

0.054

ERA

0.052

QS

0.040

PQS

0.039

BJ GS

0.027

While a pitcher’s consistency in terms of my own True Quality Starts holds the strongest year-to-year relationship, it’s still a very weak relationship overall (since 0.07 is much closer to zero than it is to one). What this tells us is that, no matter how we want to measure a pitcher’s success on a start-by-start basis, a pitcher’s consistency from start-to-start is largely unpredictable. Even if he was extremely consistent one year, he could just as easily be inconsistent the next year.

Application to Fantasy Leagues
The concept of consistency is of particular importance to owners in head-to-head leagues, who may be drafting players with the expectation that they’ll be consistent.* While this study isn’t definitive, it does seem like it would be ill-advised to count on a pitcher’s consistency. In fact, head-to-head leaguers are actually going to be doing themselves a disservice if they pass over a superior pitcher in favor one that that has a reputation of consistency. Thinking a pitcher is consistent might make us feel safer, but the point of a fantasy league is to win, and ignoring consistency to go with the better pitcher is going to give us a better chance of doing that.

 *It’s interesting to note that, while consistency is often the trait people value in a pitcher, an inconsistent pitcher is actually going to provide more value. Who is going to win more games, Pitcher A who allows 8, 0, 8, 0, 8, and 0 runs or Pitcher B who allows 4, 4, 4, 4, 4, and 4 runs? While both average the same number of runs allowed and Pitcher B is more consistent, Pitcher A is going to win more games because he’s almost assured of a win in his 0-run starts (Pitcher A would win something like 2.3 games to Pitcher B’s 1.1 games). Of course, this is a moot point since the study shows inconsistency to be largely random.  

Related Content:  Pitcher,  Head-to-head Stats

4 comments have been left for this article.

<< Previous Article
Collateral Damage: Div... (10/10)
<< Previous Column
Fantasy Article Resident Fantasy Geniu... (10/03)
Next Column >>
Fantasy Article Resident Fantasy Geniu... (10/17)
Next Article >>
Premium Article Playoff Prospectus: Th... (10/10)

RECENTLY AT BASEBALL PROSPECTUS
Premium Article Monday Morning Ten Pack: September 15, 2014
Fantasy Article Deep Impact: Week 25
Daily League Strategy: Easy Peavy
Premium Article Transaction Analysis: Rays to the Top
Premium Article What You Need to Know: September 16, 2014
Prospectus Review: 'That Foul Tip Had Better...
Premium Article Baseball Therapy: Starving Young Royals, Bat...

MORE FROM OCTOBER 10, 2011
Premium Article Playoff Prospectus: That Escalated Quickly
Collateral Damage: Division Series Injury Up...
Fantasy Article Fantasy Beat: Hellickson's BABIP: Lucky or S...
Premium Article Playoff Prospectus: Wezen-Ball: NLCS Game On...
Premium Article Kiss'Em Goodbye: Arizona Diamondbacks
Premium Article Kiss'Em Goodbye: Philadelphia Phillies

MORE BY DEREK CARTY
2011-10-17 - Fantasy Article Resident Fantasy Genius: Fantasy Rumor Mill ...
2011-10-15 - Premium Article Playoff Prospectus: NLCS Game Five: One Away...
2011-10-13 - Premium Article Playoff Prospectus: ALCS Game Four: Lineup M...
2011-10-10 - Fantasy Article Resident Fantasy Genius: Can Pitchers Contro...
2011-10-08 - Premium Article Playoff Prospectus: ALCS Preview
2011-10-08 - Premium Article Playoff Prospectus: NLDS Game Five: Brew Cru...
2011-10-06 - Playoff Prospectus: NLDS Game Four: Nothin' ...
More...

MORE RESIDENT FANTASY GENIUS
2011-10-24 - Fantasy Article Resident Fantasy Genius: Fantasy Rumor Mill ...
2011-10-20 - Fantasy Article Resident Fantasy Genius: Fantasy Rumor Mill ...
2011-10-17 - Fantasy Article Resident Fantasy Genius: Fantasy Rumor Mill ...
2011-10-10 - Fantasy Article Resident Fantasy Genius: Can Pitchers Contro...
2011-10-03 - Fantasy Article Resident Fantasy Genius: BP Fantasy End of S...
2011-09-26 - Fantasy Article Resident Fantasy Genius: Losing Speed
2011-09-22 - Fantasy Article Resident Fantasy Genius: What Sabermetrics M...
More...