Sunday, May 20, 2012

Using RE24 to Account for Situational Hitting

Many fans complain that statistics like on base percentage, slugging average and OPS don't address situational hitting.  For example, if Tigers slugger Miguel Cabrera singles with a runner on third base to drive in a run, he gets the same credit as he would for a single with the bases empty.  Some will argue that this is not fair because he contributes more to his team in the former scenario than the latter.  In this post, I will introduce a statistic which accounts for a hitter's performance  in different circumstances.

Traditional fans like to address situational hitting with Runs Batted In, but that is a team dependent statistic.  A player has more or less opportunity to drive in runs depending on who is batting in front of him.  Thus, a player gets acknowledged for driving home runs, but does not get penalized for failing to drive home runs.  So, the RBI count is not an adequate measure of situational hitting.

Other fans point to batting average with runners in scoring position, but that is based on a limited number of plate appearances.  It also doesn't consider the number of outs, the specific base runners (e.g. bases loaded versus second base only) or the type of hit (single, double, triple or home run).  Additionally, it ignores a player's performance when no runners are in scoring position. 

What we want is a statistic which gives a player credit for everything he does including situational hitting.  Batting Runs Batting Runs Above Average by the 24 Base/Out States (RE24) - found at FanGraphs - does just that.  The RE24 statistic is also sometimes referred to as "Value Added".  This metric will give a player credit for his singles, doubles, and all other events, and gives him extra credit for hits occurring with runners on base.  It even gives him points for a scenario which most other metrics ignore - moving a runner over with a ground out.

In the past, I have discussed just plain Batting Runs  (see the bottom section of the linked article).  Batting Runs is an estimate of how many runs a player contributed to his team beyond what an average hitter would have contributed in his place.   RE24 is similar to Batting Runs except that it uses base/out states in the calculation.  An example of a base/out state is "runners at first and third and one out".  There are 24 possible base/out states and RE24 takes all of them into consideration.

In the calculation of Batting Runs, a double with the bases loaded and two outs counts the same (0.770 runs) as a double with the bases empty and no outs.  Conversely, RE24 counts the bases loaded double more than the bases empty double (2.544 versus 0.632) because it does more to increase the expected runs scored in the inning.

RE24 for one at bat is the difference between run expectancy at the beginning and end of a play.  For example, suppose Cabrera bats with a runner on first and one out. In that situation, we would expect 0.556 runs to score by the end of the inning.  Assume that Cabrera then doubles, putting runners on second and third with one out. In that situation, we would expect 1.447 runs to score by the end of the inning. Therefore, Cabrera's double is worth 0.891 runs.

Summing RE24 over all of a batter’s plate appearances yields his season total RE24. For
example, Cabrera has a RE24 of 11.5 this year.  So, by that measure, he has contributed about 12 runs above what an average batter would have been expected to contribute given the same opportunities. This is a little higher than his 7.2 Batting Runs, which means that Cabrera has been especially good in situations with high run expectancy and has contributed more to his team’s runs than Batting Runs indicates.  Indeed, we can estimate that he has contributed an extra 4.3 runs with his situational hitting.


Table 1 below shows us the American League leaders by RE24.  Other columns in the table include Plate Appearances (PA), Batting Runs (BatRuns) and the difference between RE24 and Batting Runs (RE24-BatRuns).  Not surprisingly, the RE24 leader is Rangers slugger Josh Hamilton at 23.7.  Four Tigers appear in the top 20 including Cabrera (7th), Austin Jackson (13th), Andy Dirks (17th) and Prince Fielder (20th).   


Table 1: AL RE24 Leaders

Player
Team
PA
RE24
BatRuns
RE24-BatRuns
Josh Hamilton
Rangers
167
23.7
25.3
-1.6
Adam Dunn
White Sox
177
17.3
13.8
3.5
David Ortiz
Red Sox
170
16.5
16.1
0.4
Josh Willingham
Twins
154
16.1
14.3
1.8
Paul Konerko
White Sox
161
13.8
17.6
-3.8
Edwin Encarnacion
Blue Jays
175
13.7
10.8
2.9
Miguel Cabrera
Tigers
176
11.5
7.2
4.3
Carlos Santana
Indians
170
11.2
5.2
6.0
Mark Trumbo
Angels
119
11.1
12.2
-1.1
Adam Jones
Orioles
180
10.7
14.7
-4.0
Kelly Johnson
Blue Jays
177
10.2
6.7
3.5
Asdrubal Cabrera
Indians
157
10.1
10.4
-0.3
Austin Jackson
Tigers
159
9.3
13.7
-4.4
Matt Joyce
Rays
145
7.9
10.1
-2.2
Raul Ibanez
Yankees
118
7.5
6.0
1.5
Kyle Seager
Mariners
143
7.2
3.8
3.4
Andy Dirks
Tigers
103
7.0
9.2
-2.2
Joe Mauer
Twins
167
7.0
3.9
3.1
Billy Butler
Royals
167
6.8
8.2
-1.4
Prince Fielder
Tigers
172
6.6
7.0
-0.4
 Data Source: FanGraphs.com


A complete list of Tigers can be found in Table 2.   A closer look at this table shows that  Jackson leads the team with 13.7 Batting Runs.  However, he has not done as well in high leverage opportunities as he has in normal at bats.  The -4.4 in the final column shows that he has contributed an estimated -4.4 runs less than his Batting Runs indicate.  Cabrera, on the other other hand, has done better in high leverage at bats and thus moves ahead of Jackson when we account for that with RE24.     


Table 2: Tigers By RE24


Player
PA
RE24
BatRuns
RE24-BatRuns
Miguel Cabrera
176
11.5
7.2
4.3
Austin Jackson
159
9.3
13.7
-4.4
Andy Dirks
103
7.0
9.2
-2.2
Prince Fielder
172
6.6
7.0
-0.4
Jhonny Peralta
139
-0.4
-0.2
-0.2
Gerald Laird
36
-1.2
0.3
-1.5
Delmon Young
134
-2.4
-2.5
0.1
Don Kelly
58
-3.2
-3.4
0.2
Ramon Santiago
67
-3.9
-4.4
0.5
Alex Avila
125
-6.2
-1.4
-4.8
Brennan Boesch
163
-6.5
-4.0
-2.5
Ryan Raburn
120
-11.2
-10.6
-0.6
Data Source: FanGraphs.com
 

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