Washington Nationals' Offensive Analysis for 2015 (So Far)

We're about two months into the 2015 season. If you fell asleep in late March 2015 and woke up today, first, wow, and second, the Nats are probably right where you'd think: first place in the N.L. East, and six games over .500. Bryce Harper is realizing his lofty expectations, Max Scherzer is pitching like a Cy Young winner, and Stephen Strasburg is still generating material for writers everywhere (me included). Pretty good all in all, considering some of the injuries afflicting the team.

Another thing you might have missed is the roll-out of MLB's Statcast system. Statcast gives nerds like myself more information about individual and team player performance by tracking batted ball velocity/angle, route distance/efficiency, and running speed. Sorry, let me push my glasses back up my nose.

Here, I'll try to square the Nats' offensive performance so far with some of the new Statcast data we have access to. Maybe this will make sense. Maybe not!

An encouraging, but somewhat curious, offensive snapshot

When you peek at the triple slash of the 2015 Nationals, you see a .254/.324/.412 line--basically Danny Espinosa with a few less walks and extra base hits, in other words. It's been good enough for a 101 wRC+, meaning the team is about league average in the offensive department relative to their peers after park and league adjustments.

Of course, there are other numbers that give context for the team's performance. First, D.C. is third in the N.L. in runs scored, to Arizona Diamondbacks. If you were born yesterday, scoring runs is one of the most important parts of the game (preventing them is also up there). BABIP is not terribly unkind to the Nats either, as they currently rock around a .300 average on balls in play.

With just Washington's OK wRC+, near league-leading runs scored, and average BABIP figure, it's obvious one of these is not like the others. Diving a bit deeper into why that is reveals a pretty interesting fact about D.C.'s offense in the first two months of 2015, and gives us a good excuse to use some Statcast data.

Hitting them in bunches

In 2013, Dave Cameron pointed out the importance of sequencing when discussing the Cardinals' early season success. Succinctly, by analyzing a team's overall batting run value against their RE24 value (the difference in run expectancy before and after an at-bat), we can see the effect of sequencing on a team's performance. The gap between RE24 and batting runs tells us how many more (or less) runs a team scored just by bunching their hits together.

As of Monday, the top five teams in baseball benefiting the most from sequencing:

Something interesting here, right? The Nationals have scored about 37 more runs than we would have expected them to based on their context-neutral performance. That's how you sit third in the NL in runs scored with a modest offensive showing overall. Or as the young people say, #CLUTCH.

Breaking things down a bit further: the Nats were actually +26 runs to the RE24 good in April, and ended May around +10 better in sequencing (overall, the team went from the 24th best batting runs value in April to the 5th best in May). Whether good or bad in a vacuum, the team was getting hits when they needed them most.

Exit velocity

Statcast and the great work of Daren Willman at Baseball Savant let us peek into the exit velocity of batted balls for major league hitters. Most are familiar with line drive percentage as a proxy for hard hit balls, but exit velocity off the bat gives us a much more precise picture of hard-hitness.

Are the Nats hitting the ball particularly hard with runners on, helping to explain in part their favorable sequencing results? Let's find out.

Here are two big picture points to keep in mind. The first is courtesy of Tony Blengino of Fangraphs:

Popups are the one batted-ball type in which exit speed matters not one whit; it’s all about frequency. As you might imagine, authority is a much bigger deal with regard to fly balls, as there is a relatively fine line between the ultimate upside, a home run, and a garden variety out. If you take one piece of information out of this article, let it be the following one:

– Fly Balls > 92.5 MPH = .560 AVG-1.884 SLG (7.6% of all batted balls)
– Fly Balls 75-90 MPH = .077 AVG-.148 SLG (11.9%)

In short: have your fly balls come off the bat at 93 MPH or more. We've also got to consider when exit velocity becomes statistically valid enough to make some conclusions. Rob Arthur of 538 has us covered:

batted ball velocity sure stabilizes quickly. pic.twitter.com/IXGeEAxUsj

— Rob Arthur (@No_Little_Plans) May 14, 2015

By now, many of the Nats regulars have put over 50 balls in play. I looked at all of those players and searched for fly balls hit over 93MPH with nobody on base. Given the team's sequencing success, I was curious if they were simply blistering the ball in with guys on. Again, first the bases empty ("total pitches" represents total balls in play):

If you do the math, it averages to about 3.6% of "tattooed" contact (with bases empty) for players with over 50 BIP. Of that sample, the batting/slugging line was .482/1.479, with 14 home runs of the 21 hits accounted for out of the 48 sample size results. Below the averages Blengino highlights, but still pretty good results overall.

Here now is the same breakdown, except with runners on base:

Here we see that with runners on base, the same general set of players (less Yunel Escobar) has earned about 3% (average) "tattooed" contact. The batting and slugging line is a more impressive .538/1.923, owing in part to five sacrifice flies. Of the 31 balls in play, 10 were round-trippers. Harper again leads the way with such hard contact for the team.* Michael Taylor has also smoked a few.

*No shocker, but Harper is 5th among over 200 qualified players for largest percentage of fly balls hit at 93MPH and up.

Conclusions

While we don't see a striking difference between frequency of hard contact with the bases empty and runners on, the hidden value of the sacrifice fly can help explain some of the run scoring/sequencing dynamic. Five of the 31 balls in play resulted in sac flies, adding runs in place of what would otherwise be unproductive outs.

Indeed, the lowest exit velocity of a Nats' sac fly--they currently sport the 2nd-best total in the NL--was 86MPH. Not duck-your-head hard, but still pretty good. Distance is king for these outcomes; authoritative contact gets you there. And those results make Washington's overall runner-on performance look better.

So, the story here isn't that the Nats are blasting more high-exit velo fly balls with runners on than with the bases empty. But they are getting enough hard contact to generate runs even when making outs. Even if you added back in the sac flies as outs, their ISO with runners on beats their ISO with bases empty, 1.17 to .99. Statcast helps us connect some of the basic, core performance metrics with a better (but not complete) idea of why those work out the way they do.

Thanks to Baseball Savant and Fangraphs for data.

Bonus!

Because I know you want to know. Presenting the hardest-hit ball by a National this season: Harper, 116 MPH against the Diamondbacks on May 12.  Don't blink.