The Power of Plate Discipline

By Scott Barzilla
Updated: May 18, 2011

Image taken from Google Images

It’s always entertaining when old ideas and new ideas collide. Ask any fan from a bygone era and they will lament the inability of modern hitters to protect the plate with two strikes. They wax poetic about the power hitters of yore and their ability to hit for power and avoid the strikeout. So, preach to them about plate discipline and they will chime in with the chorus. Of course, the modern fan is not so concerned about strikeouts.

Generations in baseball are much longer than generations in sabermetrics. A generation ago in sabermetrics, strikeouts were not considered to be important. We bowed to the God that was walks. The current generation looks at plate discipline as a whole in a similar way that the old-timers looked at it. Those guys didn’t necessarily appreciate walks as much as we do, but the combination is something interesting.

Hear old-time baseball people talk about pitching and you would be led to believe that they get it. Just yesterday, Houston Astros President of Baseball Operations Tal Smith talked for a long time about minor league pitchers learning command of the strike zone. He wasn’t only talking about the ability to throw strikes, but the ability to locate pitches within the strike zone (in and out and up and down). Yet, people like him rarely ever talk about the hitter’s ability to do the same. Look at the numbers and that is proof enough that much of the old-guard really doesn’t pay much attention to it.

The relationship between strikeouts and walks for pitchers has been well established. It would only make sense that the reverse would also be true. However, we can’t always assume such things. Today, we are going to take a look at plate discipline for hitters and how much it relates to scoring runs. We grant that power and speed have a lot to do with scoring runs and they are not represented here. We also are not looking at 2011 numbers purely.

The goal here is unique. We want to find a correlation between the two, but we also want to look at organizational philosophy. The numbers you will see in the table below represent the 2010 numbers for the projected opening day lineups for 2011. Some of those lineups had to change before the season due to injury or other factors. Essentially, we are looking at the best laid plans of mice and men. Plate discipline is measured by dividing walks into strikeouts. For pitchers, a two to one strikeout to walk ratio is the standard. It is the same for hitters, but with regular lineups we should expect something slightly better.

	K	BB	PD	CPD	Runs
Phillies	14.3	10.5	1.36	2.15	164
Cards	16.4	10.9	1.55	1.65	210
Braves	18.0	11.6	1.55	2.19	174
Mets	17.5	11.0	1.59	1.97	166
Reds	17.6	10.1	1.74	1.95	202
Cubs	19.3	10.9	1.77	2.61	154
Rockies	18.9	10.4	1.82	1.90	168
Giants	17.1	8.9	1.92	2.61	135
Brewers	18.1	9.3	1.95	2.43	160
Marlins	20.5	9.4	2.18	2.19	168
Dbacks	22.3	10.1	2.21	2.27	163
Dodgers	18.9	8.3	2.28	2.48	144
Pirates	20.9	9.1	2.30	2.25	139
Padres	23.1	9.7	2.38	2.26	143
Nationals	21.9	9.0	2.43	2.56	145
Astros	20.0	8.0	2.50	2.84	165

You will notice that in most cases, the plate discipline numbers are worse this year than last year. That really isn’t the case. This year’s numbers include part-time players, pinch hitters, and pitchers. So really, plate discipline numbers are fairly stable over time. The Giants, Cubs, Braves, and Phillies are the only outliers and there are plausible explanations for each. The Pirates and Padres were the only teams to improve and there are plausible explanations there as well.

	Runs	PD	Rank
Cardinals	210	1.65	1^st
Reds	202	1.95	3^rd
Braves	174	2.19	6^th
Rockies	168	1.90	2^nd
Marlins	168	2.19	6^th
Mets	166	1.97	4^th
Astros	165	2.84	16^th
Phillies	164	2.15	5^th
Dbacks	163	2.27	10^th
Brewers	160	2.43	11^th
Cubs	154	2.61	14^th
Nationals	145	2.56	13^th
Dodgers	144	2.48	12^th
Padres	143	2.26	9^th
Pirates	139	2.25	8^th
Giants	135	2.61	14^th

When working with correlations, I like to start with the general and move to the specific. I’m not a mathematician and I didn’t stay at a Holiday Inn Express last night. I’m making the assumption most of you are in the same boat. So, let’s compare plate discipline ranks with ranks in runs scored:

Exact Ranking= 1

Plus or Minus 1= 7

Plus or Minus 2= 11

Plus or Minus 3= 13

Outlier= 3

Nearly half of the league was within one spot of their rankings in both runs scored and plate discipline. Nearly three-fourths were within two spots. That’s not a great correlation by any means, but we are also only about 25 percent of the way through the season. A big day or bad day by some teams could drop or elevate them two or three spots in the standings. Some representation of power would normally account for nearly half of the explanation of runs scored. Base running efficiency would explain another portion. Then, you get clutch hitting the numbers. However, we cannot deny the correlation here either.

This is where we deviate from statistics and move into one of those questions that made our brains hurt on the SAT (or GRE). If A (2010 regular plate discipline) is related to B (2011 plate discipline) and B is related to C (2011 runs scored) then A must be related C. So, looking at how teams put their “dream” lineup together is valuable in helping us determine how good management teams are in evaluating this data.