Jessica from HerRaysBaseball had a great question about Ben Zobrist yesterday.
She asked, “Also it would be interesting to take a closer look at Zobrist. Although the sample size is too small he is really starting to warm up now. I just wonder if he changed his strategy at all? There were times earlier in the year that he didn’t seem aggressive to me?”
I haven’t been paying close enough attention myself so I decided to take a look. Jessica, you’re correct that the sample size is incredibly small to take a similar look at pitch results as I did for the team as a whole. We’ll look at this in a couple of different ways and see if we can try to figure out what’s going on. Here’s a chart showing Zobie’s end-of-game triple-slash line (Batting Average, On-Base Percentage, and Slugging Percentage):
(CLICK ON ANY IMAGE FOR A LARGER VERSION)
Numerically, in the last 15 games he has raised his triple-slash from .250/.325/.356 for an OPS of .681 or a wOBA of .308 (average is around .330) all the way up to .301/.381/.417 with an OPS of .798 and a wOBA of .354. Bear in mind that those are year-long averages, but he has been able to tack on over .100 points of OPS while bringing his ragged line up to where you think he would be able to sit.
I say that he should be able to sit in that range based on the following chart:
This might appear intimidating, but let me walk you through this chart. The yellow line represents a 40 plate appearance moving average of his wOBA. This can be a good tool to show off some of his streaks as well as compare years. Note that the black dashed lines are approximate, mostly here just to give you an idea of where a year would roughly begin and end. As you can see in 2009 Ben got off to an incredible start, maintaining a nearly .500 wOBA over his first 200ish plate appearances. Of course that’s unsustainable, but once he did drop off he was still putting up league-average numbers until a couple of mini slumps at the end of the season. If you look across the range of .300<x<.400, you can see Zorilla sitting in that range for long periods of time, with the occasional boom or bust period around it. After a pretty decent couple of games, he fell off pretty hard before sitting in a normal range for a good period of time. As you can see, he’s really been playing great over the most recent stretch. There’s no telling how long it will last, but over the last 15 games he’s put up a wOBA of .439 which has worked to bring his numbers in line with what you would think Ben Zobrist is capable of doing.
Ok, so far we have looked at the results to establish that Ben Zobrist, has indeed, been scorching of late. I read Jessica’s question as more of why he’s been so much better of late. For this, we need to look at the processes. First off, I want to show what pitchers have been giving to him. For simplicity purposes I will just compare Fastball (Fastball, Cutter, Four-Seamer, Splitter, Two-Seamer & Sinker) vs. Offspeed (Change, Curveball, Knuckle-Curve, & Slider). You can see a 5-game moving average of this graphically below:
It’s pretty clear that Zobie is getting more heaters than breaking balls as the season has gone on. This could be due to a lot of reasons that I won’t delve into, but it’s a good piece of information as Ben has been a pretty good fastball hitter over his career. Two other things that I wanted to take a look at are how he’s doing on balls in play, as measured by BABIP, and how he’s doing in the BB vs. K department. As we saw yesterday, Ben has been one of the most patient batters on the team. This can be a great thing when it’s leading to good pitches to hit and getting on base via the walk, but it can backfire as it can increase strikeout rates due to all the taken strikes.
Again, we can look at a moving 5-game average to get an idea of what his streaks have looked like. After alternating between very luck and unlucky over the first half of this young season he has been pretty much lucky on his balls in play over roughly the last 15 games. On the season, I have him at a BABIP of .362 which would still rank as pretty lucky. Some previous work that I put together for last year had an expected BABIP for Zobrist of .327, so you can see that he’s still been a bit unlucky, but there shouldn’t be a huge turn-around anytime soon as these numbers work their way back to his career averages.
Lastly, I wanted to look at walks and strikeouts over the season. For this I have one last chart that shows the 5-game moving average of his daily K/PA and BB/PA.
BenZo started out the season striking out at an incredible rate, far above his career norms. This has decreased compared to the beginning of the season back into a more normal range. Meanwhile, his walk rate has been mostly around the 5-10% range with a couple of short periods north of that range. This tells me that while he has cut down on his strikeouts he has maintained his walk rate, something that can be difficult to do as a conscious effort to change one should have an effect on the other as noted in reference to pitch counts above.
Frankly, it looks like Ben Zobrist, like all players, is going to go through hot and cold periods where he’s lucky/unlucky on balls in play. It would appear that his K-rate is back under control while he is still walking at a good clip. It doesn’t hurt that he’s getting more fastballs and this could help him hit a few more dingers, which seems like the biggest issue from the fan-perspective. As a top of the order hitter, particularly in this line up, getting on base is the lifeblood that leads to runs. If the power comes then great, but it isn’t necessary as Zobie now has his wOBA up over .350 and is getting on base over 38% of the time. I would expect that OBP to stay relatively around that number and I don’t think he’s going to lose anything on his SLG going forward as it is more likely to increase. Ben Zobrist is looking like a guy that could help get this offense going, now lets go see him do it.
Thanks to Joe Lefkowitz, Baseball-reference, Fangraphs, and MLB.com for all the raw data that was used above. E-mail me if you would like to see a copy of the workbook.
P.S. I just finished putting this chart together that probably helps explain the last part of your question, Jessica, that pointed towards increased aggressiveness of late. I’d say you hit the nail on the head that he has been taking less balls, called strikes, fouling off pitches and swinging strikes (for the most part) lately and has really bumped up his In Play% from earlier in the year. This coupled with his high BABIP are the primary reasons for his recent breakout and may be explained by the increased number of fastballs he’s been seeing. I’d be interested to hear your thoughts.