Nearly a quarter of all major-league plate appearances (21.1 percent) ended with a strikeout last season. A decade ago, that number was just 17.1 percent. Isolated from broader historical context, those numbers don’t accurately reflect the scale of the league-wide rise in strikeout rate over the last decade. Pitchers struck out opposing batters at the highest rate in the modern era, which dates back to 1947 (according to Sam Miller on a recent episode of the Effectively Wild podcast), in each of the past nine seasons. Meanwhile, walk rates have remained relatively stagnant, ebbing and flowing between seven and nine percent, during the same period.
Major-league strikeout and walk rates (2002-2016)
The gradual strikeout increase has followed a linear path over the last decade, a trend exhibiting zero signs of decline. It’s easy to feel confident in that assessment because strikeout rate is one of the few defense-independent variables that a pitcher directly controls. Well, almost. It’s one of the most stable statistics on a yearly basis and we’ve known this for a long time now.
As BP alum’s Keith Woolner and Dayn Perry wrote in an essay entitled “Why Are Pitchers So Unpredictable?” for Baseball Between the Numbers back in 2006, “Measures such as walks, strikeouts and groundball percentage that reflect skills attributable to the pitcher show up as highly correlated and thus consistent and sustainable from year to year. On the other hand, measures that have a lot of factors that affect them, such as winning percentage and BABIP, have very low correlations.”
For savvy fantasy owners, well versed in sabermetrics, this is familiar material. However, I think it’s critical to re-state these core ideas because they provide important context for analyzing data from an overall landscape perspective and allow us to accurately forecast the future.
So where are the strikeouts coming from? It’s the next logical question. Fueled by the proliferation of bullpen specialization and dramatically increased reliever usage in recent years, it would be easy to point to those as the main factors driving the strikeout surge. However, that is only part of the answer. According to the raw data, displayed in graph form below, starting pitchers have experienced a similar uptick in recent years.
Starting pitcher and reliever strikeout rate comparison (2002-2016)
Like a rollercoaster ascending towards its apex, with no sign of slowing down, the biggest single-season spikes (for both starters and relievers) occurred most recently, during the 2012 campaign. Given all of the evidence, it’s particularly striking that the number of starting pitchers reaching the 200-strikeout plateau hasn’t exploded in recent years. Only 12 starters reached the lofty benchmark in 2016, and that number has never expanded beyond 18 in a single-season over the last decade. Yet, it’s still the widely used benchmark when fantasy owners reference strikeout “potential.”
As I detailed in the ERA landscape article last month, the underlying factor limiting starters from reaching the 200-strikeout threshold concerns their workload. Only 15 even reached 200 innings last year, and starters averaged just under 5 2/3 innings per-start, the lowest mark in history. While we may have to adjust our cumulative strikeout benchmarks for starters based on the current environment, it remains essential to target hurlers that can generate whiffs. So who are those elusive strikeout artists that fit the mold?
Per the Baseball-Reference play index, only 25 starting pitchers fanned at least a batter per inning, and issued fewer than four free passes per nine innings, last year. I excluded the name at the top of the play index results in the chart below for obvious reasons, but also because it made me extremely sad.
|
Rank |
Player |
K/9 |
BB/9 |
||
|
1 |
12.49 |
2.78 |
100.1 |
2.55 |
|
|
2 |
11.25 |
3.67 |
174.1 |
2.97 |
|
|
3 |
11.19 |
2.21 |
228.1 |
3.01 |
|
|
4 |
11.15 |
2.68 |
147.2 |
2.85 |
|
|
5 |
10.68 |
2.11 |
183.2 |
2.70 |
|
|
6 |
10.61 |
2.72 |
175.2 |
2.56 |
|
|
7 |
10.52 |
2.69 |
110.1 |
2.58 |
|
|
8 |
Vince Velasquez |
10.44 |
3.09 |
131.0 |
3.93 |
|
9 |
10.42 |
3.00 |
201.1 |
2.84 |
|
|
10 |
10.39 |
0.66 |
149.0 |
2.04 |
|
|
11 |
10.04 |
2.25 |
227.2 |
2.79 |
|
|
12 |
9.97 |
2.14 |
226.2 |
3.22 |
|
|
13 |
9.91 |
3.16 |
168.0 |
3.43 |
|
|
14 |
9.85 |
2.98 |
60.1 |
3.36 |
|
|
15 |
9.82 |
3.62 |
77.0 |
3.97 |
|
|
16 |
9.81 |
3.43 |
170.2 |
3.05 |
|
|
17 |
9.81 |
2.35 |
110.0 |
2.31 |
|
|
18 |
9.59 |
3.55 |
50.2 |
3.01 |
|
|
19 |
9.50 |
2.39 |
215.0 |
2.94 |
|
|
20 |
9.42 |
2.10 |
179.0 |
3.46 |
|
|
21 |
9.25 |
1.79 |
226.2 |
2.64 |
|
|
22 |
9.23 |
2.09 |
146.1 |
2.67 |
|
|
23 |
9.22 |
2.86 |
69.1 |
4.53 |
|
|
24 |
9.17 |
2.56 |
175.2 |
3.44 |
|
|
25 |
9.16 |
2.95 |
165.0 |
3.44 |
This isn’t a perfect target list, but life and baseball are filled with imperfection. Several of these pitchers still possess glaring question marks with regards to their command (Archer, Velasquez, Pomeranz and Gray), injuries/workload (Darvish, Hill, Wood, Nola, and Norris) or both concerns exist simultaneously (Urias and De La Rosa) as we inch towards the 2017 campaign. And that’s without even attempting to solve the riddle, wrapped in a mystery, inside an enigma that is Robbie Ray. The southpaw’s saga is compelling, given that the possible explanations for his struggles are harder to rationalize than the Montreal Canadiens motives for trading superstar defenseman P.K. Subban last offseason. These are problems best left intact for an intrepid explorer to solve in the future.
Among the notable arms that missed this list after finishing just below a strikeout-per-inning, but met all of the other criteria last year, were Cole Hamels, David Price, Jon Lester, Kevin Gausman, Jacob deGrom, Steven Matz, Jake Arrieta, and uber-trendy sleeper James Paxton. Of that group, only Hamels, Price and Lester eclipsed the 200-strikeout plateau based almost entirely on the high volume of innings they accrued as their team’s respective workhorses.
What about relievers? Per Baseball-Reference, 65 relievers recorded at least a strikeout per inning while accruing 50-plus innings last season. Bro, your stuff is on fire. Someone better call the fire department. Given the abundance of premium-velocity bullpen arms capable of reducing opposing batters lumber to mere kindling, the replacement level for strikeouts among relievers is exceptionally high. Only a few select arms at the tip of the spectrum like Dellin Betances, Andrew Miller, Edwin Diaz and Kyle Barraclough (all of whom posted strikeout rates in excess of 14-per-nine in 2016) are racking up enough to truly separate themselves from the rest of the pack.
The central theme of these landscape features in our annual category breakdown series is to provide fantasy owners with the context necessary to make the best possible player evaluations and determine the precise value of each hitter or pitcher. To understand the impact of potential choices, you have to understand the context in which they occur.
Strikeouts are more abundant than at any point in major-league history. From a fantasy perspective, it makes those truly elite strikeout artists, especially starters capable of shattering the 200-strikeout ceiling, even more important building blocks to assembling a fantasy staff. Once again, the rising tide has undoubtedly lifted all replacement-level boats. However, as starting pitcher workloads decline, and the gap between the truly elite performers and merely average continues to widen, aces that provide massive quantity of innings in tandem with prodigious strikeout rates have evolved into 1,000-foot ocean liners that can carry an entire fantasy staff.
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