Catcher Defense - Part 4

Today, I'm going to finish my series on catcher defense.  The first three parts of the series can be found at the links below:

Catcher Defense - Part 1

Catcher Defense - Part 2

Catcher Defense - Part 3

In Part 3, I quantified catcher defense using the CatchRuns statistic.  This included components for stopping the running game, pitch blocking and avoiding throwing and fielding errors.  Sean Smith uses a similar method with the following differences:

1. He adjusts for handedness of pitchers.
2. He uses SB per inning and CS per inning instead of CS%
3. He uses different linear weights: -0.20 for SB, +0.47 for CS, -.275 for WP/PB.TE/FE.

Smith's results are included on Baseball-Reference under catcher runs above average (Rctch).

Another option is Fan Scouting Runs (FSR) developed by Tom Tango.  Hundreds of fans including some of you completed Tango's scouting report based on their observation of fielders.  Tango has now converted the results to runs.   

Because there is some disagreement between defensive measures, I have been computing averages across measures instead of relying on just one measure.  In this case, I'll take the weighted average (WtAvg) of CatchRuns Rctch and FSR.  I'd rather rely more on the two computed measures, so I'll give CatchRuns a weight of .4, Rctch .4 and FS .2.  I'll use Victor Martinez as an example:

CatchRuns -5
Rctch -6
FSR -8

WtAvg = 0.4 x CatchRuns + 0.4 x Rctch + 0.2 x FSR = 0.4 x -5 + 0.4 x -6 + 0.2 x -8 = -6

According to the weighted average, Martinez cost his team 6 runs compared to the average catcher.  The results for other catchers are show in Table 1 below.  Yadier Molina was the top catcher by any method and his weighted average was +16.  The bottom three catchers were Ryan Doumit, Bengie Molina and Jorge Posada at -10.

Table 1 - Weighted Average of Catching Stats, 2010

Catcher Defense - Part 3

Today, I'll do part 3 of my series on catcher defense.  The first two parts of the series can be found at the links below:

Catcher Defense - Part 1

Catcher Defense - Part 2

In Part 2, I looked at metrics for stopping the running game, blocking pitches and avoiding errors.  In this installment, I'll combine all of these measures into one and try to determine how many runs each catcher saves or costs his team.  My method is not a new one, but rather a variation of what others have already done.  Others include Sean Smith, Justin Inaz and Matt Klaasen.  In fact, Matt has already done this for 2010 and his numbers are very similar to mine.  I'll add that Mike Rogers has also used a similar method evaluating catchers from 2002-2009.

There are a couple reasons why I'm going to basically repeat what others have done.  First, I want to lay out the whole method for those who haven't seen it.  I'm also going to add to it in a future post, so I want it to be clear what I'm doing.

First, we need the following statistics for each catcher: Innings (Inn), stolen bases attempted (SBA), caught stealing (CS), wild pitches (WP), passed balls (PB), throwing errors (TE) and fielding errors (FE). The numbers for Victor Martinez are:

Inn = 904
SBA = 126
CS = 27
WP = 37
PB = 4
FE = 1
TE = 5

Then we need to calculate four league rates:

CS Percentage = Lg CSRate= CS/SBA = .2762
WP plus PB per inning = Lg WPPBRate = (WP + PB)/Inn = .0452
TE per inning = Lg TERate = TE/Inn = .0055
FE per inning = Lg FERate = FE/Inn = .0016

Now, we can use the above numbers as the basis of the calculation of runs cost/saved by Martinez.

We know that runners attempted to steal on Martinez 126 times in 2010.  Based  on the .2762 Lg CSRate, we would expect the average catcher to throw out 126 x .2762 = 34.8 runners in 126 opportunities.  Martinez threw out 27 runners attempting to steal, so his caught stealing rate above/below average (CS+) was -7.8.

Based on linear weights, the average caught stealing is worth 0.63 runs (0.44 for the CS plus 0.19 for the SB not achieved).  So, caught stealing runs above average (CSRuns) can be computed by multiplying CS+ by 0.63.  For example, Martinez had -7.8 x 0.63 = -4.9 CSRuns.  This means he cost his team about five runs more than what would be expected from the average catcher given the same opportunities. 

Similar calculations can be done for WP and PB.  Martinez caught 904 innings in 2010.  Based on the .0452 Lg WPPB rate, we would expect the average catcher to allow .0452 x 904 = 40.9 WP and PB in 904 innings.  Martinez allowed 41 WP and PB, so his WP plus PB above/below average (WPPB+) was +0.1.

Based on linear weights, a WP or PB costs -0.28 runs.  Thus, WP plus PB runs above/below average (WPPBRuns) is equal to WPPB+ x -0.28.  Martinez had 0.1 x -0.28 = -.03 WPPBRuns in 2010.  So, he cost his team .03 runs more than expected in preventing WP and PB.  Of course, that is essentially no runs, but I left the decimal in there in order to illustrate the calculation.

Catcher throwing error runs (TERuns) are calculated the same way as WPPBRuns.  A catcher throwing error typically occurs when a catcher attempts to either throw a runner out stealing or pick off a base runner.  Since the result is often similar to a WP or PB, we can use the same linear weight for TE as we do for WP and PB (-0.28).

Catcher fielding error runs (FERuns) are calculated the same as WPPBRuns and TERuns except that a different linear weight is used.  A catcher fielding error generally has a similar effect to errors used by other fielders (about a half run), so we can use -0.50 instead of -0.28.  Martinez had 0 TERuns and 0.2 FERuns.

(Note that the linear weights I used for errors are different from what others have used.  There doesn't seem to be a consensus and I really am not sure whether my weights are better or worse than others.  It turns out that catcher errors are so infrequent that the choice of linear weights rarely makes much of a difference in the final result)  

Finally, all of the above run values can be combined to arrive at catcher runs saved above/below average (CatchRuns):

CatchRuns = CSRuns + WPPBRuns + TERuns + FERuns

For Martinez, that is -4.9 = 0.0 + 0.0 + 0.2 = -4.7.  So, by this method, Martinez cost the Red Sox 4.7 runs more than the average catcher.

The statistics for all catchers with at least 500 innings in 2010 are shown in the table below. Cardinals catcher Yadier Molina was number one with 14.9 runs saved.  His brother Benjie was at the bottom (-13.5).  Alex Avila finished at -1.2.

The raw data for this article were abstracted from Baseball-Reference.com

Table 1: Catcher Runs Saved/Cost in 2010

Catcher Defense - Part 2

In an earlier post, I touched upon the difficulty of measuring pitcher handling by catchers.  Numerous Studies have been done regarding this issue, but none have shown conclusively that pitcher handling is a skill that can be repeated from one year to the next.  This is perplexing because so many people inside the game insist that pitcher handling is very important and that some catchers are significantly better at it than others. One possible solution is John Dewan's catcher earned run saved statistic described in my previous post.  However, that measure is a work in progress and is limited by small sample sizes for pitcher/catcher duos.

Other catcher duties are easier to quantify than pitcher handling because they are somewhat independent of pitchers.  This includes throwing out base runners, preventing passed balls and wild pitches and avoiding throwing and fielding errors.  Pitchers do have some influence over these rates.  For example, a catcher who frequently catches a knuckleball pitcher will probably have a high number of wild pitches and passed balls. 

Also, since left-handed pitchers are typically better at holding baserunners than right-handed pitchers, a backstop catching a heavily left-handed staff will tend to have better success preventing steals.  Still, the relative frequencies of stolen bases, caught stealing, wild pitches, passed balls and errors tend to be fairly consistent from year to year for many catchers, suggesting that these measures probably represent real skills.

Two statistics that measure the ability of catchers to control the running game are stolen bases attempted per nine innings (SBA/9) and caught stealing percentage (CS%).  Victor Martinez had a 1.25 SBA/9 catching for the Red Sox last year.  This means that, base runners attempted to steal 1.25 bases per full game when Martinez was catching.  That was substantially worse than the league median of 0.80  The only catcher who was worse was Jason Kendall of the Royals (1.26).The best was Rod Barajas (0.46) who split time with the Mets and Dodgers. 

Martinez had a CS% of 21% meaning that he threw out 21 percent of base runners attempting to steal.  This was less than the MLB median of 29%, but he was far from the worst.   Chris Snyder of the Diamondbacks and Pirates threw out only 9%.  The Cardinals' Yadier Molina was the best at 49%.

Pitch blocking can be measured by wild pitches and passed balls per nine innings (WPPB/9).  Wild pitches are included in the calculation, as it is often difficult to distinguish between wild pitches and passed balls and it is possible that official scorers give some catchers or pitchers the benefit of the doubt based on reputation. 

Martinez's 0.41 WPPB/9 was right at the MLB median.  Phillies catcher Carlos Ruiz was the best (0.16) and Angels backstop Jeff Mathis (0.73) was the worst. 

Finally throwing errors per nine innings (TE/9) and fielding errors (FE/9) per nine innings are used to measure error prevention by catchers.  Martinez had .05 TE/9 and 0.01 FE/9, which was close to the MLB median in both cases.  Catcher errors are infrequent and some made no throwing errors or no fielding errors.  Russell Martin of the Dodgers had the worst TE/9 (0.10) and Adam Moore of the Marlins the worst FE/9 (0.05). 

How did Alex Avila rank?

SBA/9 = 0.75 (slightly better than the median)
CS% = 32% (slightly better than median)
WPPB/9 = 0.56 (worse than median)
TE/9 = 0.02 (better than median)
FE9 = 0.01 (better than median)


In a future post, I will combine all of the above metrics into one number representing a catchers overall performance beyond the elusive pitch handling skill.

The raw data for this article were abstracted from Baseball-Reference.com.

Catcher Defense - Part 1

The catching position is the most difficult to quantify defensively.  Instead of the physical range characteristics cited for infielders and outfielders in earlier posts, the handling of pitchers is believed my many insiders to be the most important skill of any catcher.  By pitcher handling, I mean studying opposing batters, game calling, understanding pitcher abilities and tendencies, helping the pitchers maintain focus and other duties unique to the catching position.  These things are hard to measure because it's difficult to know how much of good or bad pitching is due to the pitcher and how much is due to the catcher. 

Bill James attempted to measure pitcher handling when he created the catcher ERA (CERA) statistic in the 1980's.  CERA is simply the ERA of a team's pitching staff when a given catcher is behind the plate.  The idea is that pitching staffs should have lower ERAS when a superior defender is catching. 

A limitation of CERA is that different pitcher/catcher combinations do not accumulate enough innings over the course of a season for it to be considered reliable.  Another concern is that it can be biased by which pitcher the catcher's catch.  For example, if a catcher was the personal catcher for the team's best pitcher, his CERA would be artificially deflated by the quality of the pitcher, instead of his own skill. 

To address the bias issue of CERA, John Dewan introduced the earned runs saved statistic in The Fielding Bible - Volume II.  Simply stated earned runs saved is the number of earned runs that a catcher saves his pitching staff.  For example, Mike Mussina, had the the following statistics pitching for the Yankees in 2008:

IP 200 1/3
ER 75
ERA 3.37

Jose Molina caught 190 1/3 of Mussina's innings and the Mussina/Molina combination posted the following numbers:

IP 190 1/3
ER 68
ERA 3.22

Now, suppose Mussina actually had an ERA of 3.37 (his ERA for the season) in the 190 1/3 innings that Molina caught.  In that case, the Mussina/Molina duo would have allowed 71.3 earned runs.  Subtracting the 68 actual runs allowed by the battery from the 71.3 yields 3.3 earned runs saved for Molina in games pitched by Mussina.  Summing Molina's earned runs saved for all the pitchers he caught yields 31 earned runs saved for the season.  Using the same technique, Brandon Inge cost his staff 37 runs (-37) in 2008.

Because it adjusts for quality of pitchers (based on their ERA for the season), earned runs saved is less biased than CERA.  However, it is still limited by small sample sizes for pitcher/catcher combinations.  Thus, Dewan arrives at a more conservative estimate by regressing to the mean:

(1)  He multiplies earned runs saved by .33 (31 x .33 = 12.2).  He admits that the .33 is arbitrary.  The idea is to give credit to Molina for saving runs without relying too heavily on an extreme number produced by small samples. 

(2) He further regresses to the mean based on the number of innings caught.  The more innings a catcher catches, the more credit he gets for his earned runs saved.  A full season is roughly 1,440 innings.  Molina caught 737 innings which is roughly half a season.  So he regresses by half ( 12.2 x .5 = 6.1)

Dewan also adjusts for ballpark.  In Molina's case, he ended up with 5 adjusted earned runs saved for the season. The adjusted earned runs saved can be found at Baseball-Reference (under RerC).  The 2010 leaders and trailers are shown in Tables 1 and 2 respectively. 

Table 1: Catcher Adjusted Earned Runs Saved Leaders for 2010

Table 2: Catcher Adjusted Earned Runs Saved Trailers for 2010

According to these numbers, new Tigers catcher/designated hitter Victor Martinez cost the Red Sox pitchers 5 runs with his pitcher handling in 2010.  Alex Avila cost the Tigers staff 2 runs last year.  Gerald Laird saved the Tigers 2 runs.  

Other facets of catcher defense beyond pitcher handling will be explored in a later post. 







   

Tigers Roster Taking Shape

The Tigers are probably not done shaping their roster this off season.  They may still add another starting pitcher, another outfielder or even a second baseman.  With the holidays fast approaching though, it probably won't happen soon.  So, let's take a look at the possible opening day 25-man roster.  First, the starting line-up:

CF Austin Jackson
LF Ryan Raburn
RF Magglio Ordonez
1B Miguel Cabrera
DH Victor Martinez
SS Jhonny Peralta
3B Brandon Inge
2B Scott Sizemore
C Alex Avila

The biggest question is second base. If Carlos Guillen is healthy, he would probably play second base and bat second with Raburn moving to the sixth spot and everyone behind him moving down a spot. If Will Rhymes wins the job, he would also probably bat second.

The bench would look like this:

Ramon Santiago IF
Don Kelly UT
Casper Wells OF
Clete Thomas OF

Some might be wondering why I left Brennan Boesch off the bench, but I think they'd rather have him starting in the minors than sitting on the bench.  They will need a right-handed batter to effectively platoon with Avila.  Against RHP, Avila will be the catcher, Martinez the  designated hitter and Ordonez the right fielder.  Against LHP, it will be Martinez behind the plate, Ordonez at DH and somebody else in RF.  Right now, I'm guessing that somebody will be Wells.

If Guillen is the starting second baseman, he'll need days off, so they would probably carry an extra infielder.  In that Case, Sizemore might back up Guillen and Kelly or Thomas would be out.

Barring another acquisition, there is not much question about the starting staff:

Justin Verlander
Max Scherzer
Rick Porcello
Phil Coke
Armando Galarraga

I do expect them to make a move, although probably not a big one.  Brad Penny? It's also possible that Andy Oliver wins a job with a strong spring, but he probably needs more seasoning.

The bullpen:

Jose Valverde
Joaquin Benoit
Ryan Perry
Joel Zumaya
Brad Thomas
Daniel Schlereth
Alberto Alburquerque

The twelfth spot is really up for grabs. I'm saying Alburquerque because I like his name, but it could just as easily be John Bale, Chris Oxspring or any number of other names.