In defense of the K — or how I learned to stop loving groundballs


"Relax, all right? Don't try to strike everybody out. Strikeouts are boring! Besides that, they're fascist. Throw some groundballs — it's more democratic." — Crash Davis, in 1988's classic baseball flick "Bull Durham."
This piece of advice from Kevin Costner's character has been translated into nearly every ballpark in America, as fans and commentators alike lament a struggling pitcher's inability to just throw the ball over the plate. Even if they hit the ball, it's not another boring walk, and besides, you have seven guys standing behind you who are covering most of the field; as long you keep the ball in the ballpark, odds are that the hitter is going to make an out. Trust your defense, pitch to contact and, most importantly, work deep in the game.
But is putting trust into your defense actually a good strategy? After all, while most balls in play become outs, almost every strikeout becomes an out — there are rare times when a batter does reach on a strikeout due to a wild pitch or passed ball — and a pitcher's job is to rack up as many outs as he can, while allowing as few runs as he can in the process. Are strikeouts an inefficient way of collecting outs, and would a pitcher be better off trading them in for those democratic groundballs if he wants to get as many outs as possible while staying within his pitch count? Let's dive into the numbers.
Overall, there are 105 starting pitchers who have thrown enough innings to qualify for the ERA title. The average pitcher in this group has thrown 3.8 pitches for every batter faced, so given today's rough guideline of 100 pitches per game for a starter, a pitcher can be expected to face about 26 batters per game, or get through the entire batting order nearly three times. However, because some batters reach base, the average qualified starter has required 5.3 pitches for each out he has recorded, meaning that he records about 19 outs per start, or 6 1/3 innings pitched.
Do groundball pitchers get more bang for their buck, as is often suggested? Let's take a look at those 105 starters broken into quartiles based on groundball percentage this year.
Quartile | GB% | Pitches Per Out | Pitches Per Batter |
---|---|---|---|
1 | 55% | 5.2 | 3.7 |
2 | 49% | 5.3 | 3.8 |
3 | 44% | 5.4 | 3.8 |
4 | 39% | 5.5 | 3.9 |
Conventional wisdom is confirmed; pitchers who specialize in getting groundball outs throw fewer pitches to each batter they face, and they require fewer pitches per out they record. Note that San Francisco Giants pitcher Tim Hudson — currently at a stunning 3.3 pitches per batter faced and just 4.2 pitches per out — is No. 3 in the majors in groundball rate. Hudson has basically perfected the all-strikes-all-the-time, trust-my-defense strategy, and it's one of the reasons he's been a stellar performer for the Giants so far this year.
But we have to issue a caveat here. Note the very small differences between the top and bottom quartiles; extreme groundball pitchers have saved an average of one quarter of one pitch per out recorded relative to extreme fly-ball pitchers. With a 100-pitch guideline for both groups, that means the top quartile would save enough pitches to record one extra out per start over the bottom quartile, and these are the guys at the polar ends of the spectrum. In the middle, the difference between moving your groundball rate a few ticks hardly matters at all.
And trading strikeouts for groundballs comes with its own downside, as it might save you a few pitches, but it costs you some runs in the process. Here are the full results for the 2013 season, again qualified starters broken up into quartiles, but this time, we're going to show ERA, FIP, and xFIP relative to league average for each group.
Quartile | GB% | ERA- | FIP- | xFIP- |
---|---|---|---|---|
1 | 52% | 97 | 94 | 93 |
2 | 46% | 87 | 88 | 92 |
3 | 44% | 92 | 93 | 96 |
4 | 38% | 97 | 101 | 101 |
Over a full season last year, the extreme groundball quartile posted an ERA that was only three percent better than the league average, the same mark posted by the group with the lowest groundball rate. The two middle quartiles, made up of pitchers who get roughly a league average number of groundballs, were easily better than both extremes.
And this is where we see that Crash Davis' advice actually falls apart to some degree. His suggestion to pitcher Ebby Calvin "Nuke" LaLoosh (played by Tim Robbins) is to trade strikeouts for groundballs in order to get him to stop throwing so many pitches out of the strike zone, but in fact, groundballs primarily come from pitches down out of the strike zone; if you elevate a pitch enough to be called a strike, a major-league hitter can probably get under it enough to get it in the air with some frequency.
Extreme groundball pitchers don't tend to throw more strikes than other pitchers; they actually throw less. This year, the top quartile in groundball percentage is throwing strikes 63 percent of the time, the lowest mark of any of the four groups. That 63 percent strike rate matches the total for the groundball quartile from last year, while the other three groups each managed to throw 65 percent of their pitches for strikes. Pitchers who pitch in the strike zone — what Davis was trying to get LaLoosh to do — and up getting more strikeouts than groundballs, and not the other way around.
Hudson might be the ideal Crash Davis pitcher, but he's also something of an aberration. Most pitchers can't pound the bottom of the zone the way Hudson does, and his pitch efficiency comes more from his command than it does from the fact that he gets a lot of groundballs. And giving up more runs for the right to shave a tenth of a pitch off each out recorded isn't a good trade-off.
One of the reasons strikeouts are surging in baseball is because teams have learned that advice like what Crash Davis told Nuke LaLoosh is actually counterproductive to winning baseball. Maybe strikeouts are boring and fascist, but they're also just really effective.
