We all heard the hype train rolling into town when the Nationals were preparing to select Stephen Strasburg with the number one pick in the 2009 draft. His fastball was going to put Nolan Ryan's heater to shame. He had the potential to develop a changeup that Pedro Martinez would be jealous of. His breaking ball also profiled as yet another potentially devastating out pitch. By most accounts, he would at least threaten to supplant Walter Johnson as the greatest pitcher a D.C. squad has ever seen.
Five years later, the Nats have been left with a pitcher who has merely been excellent rather than a player whose path is leading to a unanimous first ballot Hall of Fame election. Where did the Nats go wrong? The shame!
Appreciate What We Have
Since the start of the 2010 season (Strasburg's rookie year), let's have a look at where Strasburg ranks among all MLB starting pitchers in some key categories.
|Statistic||Strasburg's Numbers||MLB Rank|
So... What do we take from those numbers? He hasn't been the best starter in the majors, which the hype train led us to believe he would be. He's been great in terms of traditional rate stats like ERA and WHIP. He's been excellent in terms of FIP, which normalizes BABIP. He's been the best in the league by xFIP, which also normalizes HR/FB rate to 10.5%. He also leads the majors in SIERA (Skill Independent ERA... I'll link a description), which is another component ERA that attempts to measure pitchers based on their underlying skill.
(Why) Is he (really) struggling in 2014?
Of course, some of the problem isn't what he has done since arriving in D.C. It's what he's doing right now. Here are his 2014 ranks in those same categories (minus fWAR/100 IP):
|Statistic||Strasburg's Numbers||MLB Rank|
Once again, we see that stats like FIP, xFIP, and SIERA love him. Perhaps he isn't ranked quite as highly in those statistics as he has been over his career, but statistics that look at his underlying skill and eliminate BABIP and HR/FB rate say that he's having yet another excellent season. Unfortunately, he's had massive problems with both of those statistics. Let's see if we can find a reason why.
Strasburg has allowed a .341 BABIP in 2014, which is fourth highest in MLB. The league average BABIP is .292. Strasburg's career BABIP is .302. While luck is often brought up when BABIP is discussed, I'm not ready to pin it all on luck. First, let's have a look at his batted ball charts.
I've led with his BABIP for each season, which we can see has really fluctuated. Again, in a luck neutral environment, we can usually expect the league average BABIP to be somewhere between .290 and .295. There's some question as to how much a pitcher can really control this, but we can certainly expect that the type of hit will have an effect. For many of you, this will be nothing new:
- Line Drives (LD%) are the most likely to result in a hit.
- Ground balls (GB%) fit somewhere in the middle. They're far less likely to result in a hit than a line drive, but more ground balls find a hole on the infield than fly balls.
- Fly balls (FB%) are the most likely event to result in an out. The majority of fly balls tend to find a glove and get caught. A few more (generally in the 10-10.5% range) find their way over the fence and don't count towards BABIP because they are home runs.
Since Strasburg combined for just 17 league starts (SSS) in 2010 and 2011, I'm not going to pay a lot of attention to those seasons. Instead, let's focus on the past three seasons, where Stras has had a slightly high .311 BABIP followed by a very low .263 and then this current season's ridiculous .341. What do the components tell us?
- We'll note that his 2012 LD% was a touch high (22.7%... league average was 20.9% that year), so we should expect that this could have helped lead to a higher than average BABIP (.311... check!). His 2013 LD% was likely an outlier based on everything else we've seen from Strasburg in his career, but his LD% was 3.7% lower than the league average, which likely helped keep his BABIP extremely low (.263... check!). In 2014, his LD% has been a career worst 24.0%, which is 3.4% higher than the league average. We're seeing the results in his .341 BABIP (again, check!).
- Save for the 2013 season, his GB% has been roughly league average (45%). This should lead us to believe that his GB% isn't necessarily the problem. It was instrumental in the 2013 season that appears to be an outlier, but his GB% has been neutral in 2012 & 2014.
- His FB% is actually a touch low, which would likely hurt his BABIP a touch as well (again, this is the most likely BIP to become an out). The kicker for this season, though, is that more of those fly balls are going over the fence. While those home runs don't raise his BABIP, the combination of a low fly ball rate and a high HR/FB rate means that fewer of those fly balls he's allowing are turning into outs.
Strasburg has owned a slightly high HR/FB rate for the past few seasons, but it's typically been less than 1% above the league average (~10.5%). This season, his HR/FB rate is at 14.1%. This may be a bit inflated after the ridiculous 80% HR/FB rate in Friday's start at Atlanta, but it's still one of the things that may be skewing a surface stat like ERA farther above what his FIP and (in this case) xFIP would suggest we should expect of him moving forward. Strasburg's 14.1% HR/FB rate is the seventh highest in the majors this year.
Apart from luck, what could be causing his problems with BABIP and HR/FB rate? Let's look at the simple answer.
While simple poor luck has to account for some of the BABIP (and maybe even a small portion of the HR/FB rate), there is another factor we have to consider. Strasburg's average fastball velocity has declined a bit in each season of his career so far. This isn't really all that unusual, and he's still one of the hardest throwers in the league. In fact, I was watching the Royals-A's game last night (Yordano Ventura was pitching for Kansas City). The A's broadcast showed a graphic of the pitchers with the top average velocity in MLB this season. Strasburg was sixth.
In 2014, he's averaged 94.5 MPH (down from 95.2 MPH last season). While Pitch Values indicate that the gradual decline in velocity hadn't really affected his fastball's effectiveness much in the past few seasons, that effectiveness has completely fallen off of a cliff in 2014. Here's another visual showing the performance in terms of Runs Above Average with Strasburg's three primary pitch types:
I've left the curveball and changeup in this table so that we can see just how effective that changeup has become. It's devastating, and has gradually become his best pitch. He's still using his curveball effectively, but not as effectively as he had in the past two years. The fastball, however, has gone from a pitch that has always been worth a handful of Runs Above Average to a pitch that has been one of the worst in the majors in 2014. In fact, among 89 qualifiers for the ERA title, Strasburg's fastball ranks 83rd in Runs Above Average.
Strasburg has thrown the fastball less often this season (59.1%) than he has in the past (61.7% career), but he still throws it well over half the time. Most major league pitchers do. If opponents keep squaring it up, that's likely to lead to continued struggles.
As for movement, all of the Pitchf/x data that I can find seems to indicate that he's gained a little more movement on his fastball (we might anticipate more movement to compensate for the drop in velocity), but it hasn't been all that significant. He's had slightly more average vertical movement (8.97 vs. 8.84 from 2012-2013) and horizontal movement (5.96 vs. 5.32 from 2012-2013) in 2014.
This doesn't really explain a lot (even to me as I write it), but it does leave me wondering just how the pitch has gone from 6.4 Runs Above Average (23rd in MLB) in 2013 to -11.1 Runs Above Average (or 11.1 Runs Below Average, if you prefer) and 83rd best among 89 qualifiers with a 0.7 MPH drop in velocity.
Plate Discipline Against
I'm going to spend very little time on this section because the data doesn't really explain much of anything.
- Opponents are chasing more often than they have against Strasburg the past two seasons.
- They're not making a significantly higher amount of contact either on pitches in or out of the zone, so this should actually be a positive.
- Stras is actually getting more fist pitch strikes over than he did in either of the past two seasons, which defies the myth that he's been falling behind and throwing opponents challenge fastballs that get crushed.
- His swinging strike rate has been as high as it's been since his rookie season in 2010.
We'll show you a series of tables here detailing "two pitchers." They are Stephen Strasburg at home and Stephen Strasburg on the road. I'm going to show all three seasons in which he's made at least 28 starts. We'll see that the road woes haven't been limited to this season, but we'll also see that he's more than capable of pitching well on the road. We're going to work backwards, since everyone's focused on this year.
What can we draw from this?
What should we expect the rest of the season?
|Date||Opponent||Opp. Runs Rank||Opp. wOBA Rank|