Just last month I wrote about how Denard Span was performing offensively. In that piece I concluded that Span was an average contributor on offense, which made him a valued member of the Nationals. I closed the piece saying "he probably just shouldn’t be batting leadoff, but that’s a discussion for another day." Well 36 straight games on-base later and that statement is no longer true. Now I still believe I was correct at the time of the article, so what has changed since that first post? To find out let's take a comparison of the stats I noted in the first piece and what they look like now.
What a difference a month can make. His batting average is up 38 points, on-base percentage up 44 points, wOBA up 29 points. Span went from an league average at-best hitter to a well above-average hitter in nearly every statistical category. The first thing the aspiring sabermatrician will probably notice here, after being astounded by the jump we just noted, is the big jump in Span's batting average on balls in play, from .296 to .338. Immediately, we suspect that this is a large part of Span's statistical boost.
The second thing one might notice is that Span's walk rate has increased by 1.20%. A big part of the previous piece was noting how Span's walk rate had dropped from 9.5% for his career in Minnesota, and 8.3% in 2012, to a paltry 6.3% in 2013 and 6.7% at the time of that post. While 7.9% is still a bit lower than the numbers he posted in Minnesota, it is at least equal to the league average walk rate among position players.
So we can see the big improvements in Span's overall offensive numbers and when we look one level deeper we can see where the performance boost is coming from. Now on to the important question: can he keep it up?
The immediate reaction to seeing a .338 BABIP is no, he can't. Now that comes with a number of caveats. One, just because BABIP usually regresses back to a batter's average over time, doesn't necessarily mean it will over the course of a 162 game season. With a statistic as variable as BABIP, even just a 600 plate appearance sample size usually isn't enough to see full stabilization. Of course, the likely outcome is that it will begin to regress, but that comes with another caveat. His BABIP on July 8 had the same issue as his BABIP now does, just on the other end of the spectrum. Span's career BABIP is .321 and in the last two seasons it was .315 and .313. So while .338 is likely too high, .296 was also too low. So Span will likely see his batting average on balls in play come back down over the course of the remainder of the season and settle in around that .315-.321 range.
As we can see above, Span's contact rate is still about the same as it was a month ago, and is actually a tenth of a percentage point higher. While that is doing wonders for his strikeout rate, it still means he is highly dependent on a good BABIP to be a good hitter, as I stated in the previous piece. There are two places a contact heavy hitter can get some added value though, in his walk rate and in his ISO. To no one's surprise Span isn't a power hitter and after being a bit inflated, his isolated slugging percentage has dropped back to near his career average of .104. So he isn't going to get much added help from extra base hits.
So, just like in the previous post, our focus is on his walk rate. The news on that front still isn't great. Span is swinging at pitches outside of the strike zone even more than he was on July 8. Now, it probably won't drop all the way down to 6.7%, which was a rate more befitting his 28.1% O-Swing% in 2013. So like we saw with Span's BABIP, his walk rate probably is at its peak now and will likely regress, but still will likely stay above what it was on July 8.
And if we take a look at Span's Steamer and ZiPS projections we can see these notions reflected perfectly in his rest of season projections.
Both projection systems peg Span's rest of season BABIP at around .315. They differ a bit on walk rate, with Steamer taking the more optimistic outlook, but both see it being slightly lower than it is currently. However, another truth can be seen when we look down to the next line for Span's updated full season projections. Just because Span can't keep up his superb hot streak, it doesn't mean that it hasn't happened. Even when we project the remained of his season out to a more reasonable level, he still looks to put up great numbers for the season as a whole.
In the last post, we concluded that why Span isn't the great leadoff hitter it was hoped he would be, he was still a valuable player with about league average hitting, great baserunning and above average defense. Now, with a hot streak under his belt Span has provided above average hitting to go along with his great baserunning and above average defense. That combination has put him on track for his most wins above replacement in a season ever. The kind of surplus value the Nationals need when the players they counted on to provide the most value, Zimmerman and Harper, have struggled with injuries all season. And yes, this time, Span has proven that he can and should be batting leadoff for the Nationals.