B-E, A-G-G-R-E-S-S-I-V-E.

Now I’ve got that Faith No More song stuck in my head.

* Side note: Any FNM fans out there? What’s your favorite album? I’m a big fan of Angel Dust but Album of the Year always hits a soft spot for me as well.

After initially hitting on it some in my last post, I got to wondering about Zito’s constant comments of ‘not being aggressive enough’ and how they related to his success, or lack thereof. I decided to take all of his data from 2002-2008* and plot his Strikes% or how many times hitters saw strikes from Zito in a game. My theory was that the more strikes a pitcher is throwing — called strikes, swinging strikes, pitches fouled off — the better that pitcher should do. That seems incredibly simple and it is.

* I didn’t use his 2001 season as a starter because Fangraphs didn’t go back that far for gamelogs. You can call me lazy but FanGraphs has a really nice feature where you can export whole sets of data as an Excel file. Thanks to FanGraphs, without your Excel export feature this would have taken way more longer than the couple of hours it took.

But, putting simplicity aside, I wanted to know at which percentages does Zito have the best chance of succeeding as a pitcher. Is he trending in a new direction? Is that direction good or bad? These are a few of the questions that I wanted to answer before I set out to try and understand what it really means for Zito to be ‘aggressive’.

Operationalization

I wanted to define that various levels of control that Zito has. I decided to break it down into the following five categories.

1. Walk Machine – Less than 55% strikes in a game.
2. Nibblin’ - 55-60% strikes in a game.
3. Average - 60-65% strikes in a game.
4. Aggressive - 65-70% strikes in a game.
5. Strike Machine – Greater than 70% strikes in a game.

For comparison, Zito’s career Strike% has been as high as 64% in in ’02 — the Cy Young year — and as low as 59% in ’06. As of now, his career Strike% is at 61%.

Let’s run through the numbers and see what I found.

I’ll go ahead and note that I’ve added BB/9, K/9, and K/BB for each category in addition to the overall numbers for that category. I generally dislike X/9 stats because they extrapolate everything to a theoretical 9-inning game, percentages based on PA’s are more accurate but for our needs, it’s a quick and dirty stat that will give us some context.

Walk Machine
19 Career Starts
6.61 ERA, 96.2 IP, 71 ER, 67 SO, 84 BB
7.82 BB/9, 6.24 K/9. 0.80 K/BB

Nibblin’
77 Career Starts
ERA 4.43, 459.1 IP, 226 ER, 312 SO, 243 BB
4.76 BB/9, 6.11 K/9, 1.28 K/BB

Average
82 Career Starts
3.33 ERA, 534.2 IP, 198 ER, 377 SO, 189 BB
3.18 BB/9, 6.35 K/9, 1.99 K/BB

Aggressive
44 Career Starts
ERA 3.36, 299.2 IP, 112 ER, 224 SO, 67 BB
2.01 BB/9, 6.72 K/9, 3.34 K/BB

Strike Machine
6 Starts
3.52 ERA, 38.1 IP, 15 ER, 35 SO, 3 BB
0.7 BB/9 , 8.22 K/9, 11.67 K/BB

Discussion Points

1. You can see that for Zito’s career — and I’m assuming this is true for every pitcher — the more strikes thrown the better. Just by increasing strikes thrown — swinging, fouled off, or called — by an additional 5% to go from Nibblin’ to Average resulted in taking off a little more than a full run from Zito’s ERA. That’s the difference between a back-end rotation starter and a front-end rotation starter.

2. The categories of Average and Aggressive are nearly identical. I found this interesting. The K/9 rates for both are very similar and the only noticeable difference is the BB/9′s, Aggressive was nearly a walk per nine innings lower.

3. Strike Machine was very good but it’s a very small sample. Only 38.1 innings classifies as a Strike Machine. The ERA for this category is actually higher than Aggressive and Average. Chalk it up as a small sample size because 6 starts is microscopic over the season for a pitcher.

4. Over his career when Zito is throwing strikes at a percentage of 60%+ he’s been a successful pitcher but remember that the bulk of these numbers come from his earlier days in Oakland when he was playing in front of superb defenses — not the case with the ’08 Giants.

To get a visual, I plotted the Strikes% from Zito from ’02 to the current season of ’08. I added a linear trend line to show any trends.

You can see that for most of this graph, Zito was above the 60% strike rate that we found he was most successful at. But, if you’ll notice the trend is moving downward and he’s started to dip under that magical 60% mark. I’ll also add that throwing strikes is clearly beneficial for a pitcher, but a theory of mine is not only has Zito started to loss control, but that he’s lost pitch quality as well. The dip in velocity is one indicator of that loss of pitch quality.

During Zito’s peak years of ’01-’03 he played in front of one of the best defenses in the game. In 2001 Oakland was ranked as the 2nd best defense in the game by defensive efficiency. In 2002, they were 6th and in 2003, they were 2nd. The Oakland defense surely helped Zito in ’03 when hitters make contact against him 83% of the time, a career high for Zito at that time. Hitters are now making contact against Zito at a rate of 84%, a new career high.

Zito’s strikes swinging percentage has also dipped this year. I’ve taken strikes swinging to be a good indicator of pitch quality. The better a pitch is, the harder it should be to hit it. Earlier this year Zito’s strikes swinging percentage was around 8%, which is extremely low for a guy not trying to induce groundballs over and over. His strikes swinging percentage has raised some, it’s now up to 11% but that’s still a career low for Zito. During his peak years of ’01-’03, Zito’s strikes swinging percentage was 17%, 16%, and 12%. Once again, the Oakland defense in ’03 must have really helped out Zito.

So, we are seeing a pitcher who’s trending downward in the ability to consistently throw strikes and a pitcher who’s letting hitters make more contact against. You then stick that pitcher in front of one of the worst defenses in the National League and you’ve got the 2008 version of Barry Zito.

Here’s the plot for Zito’s strikes percentage since he joined the Giants.

We learned above that Zito experienced the most success when he was throwing strikes at rate of 60% or greater. But, that comes with a new caution. Zito has lost something on his pitches and he’s playing in front of a poor defense. So, the old rule of finding success at 60%+ may have changed and it’s not something we’ll be able to figure out in the present. But, for arguments sake, say that we stuck to that rule of 60% or greater for his strikes thrown and you can see one of the reasons why Zito has struggled since he came to the Giants. He’s not throwing strikes as much as he used to. Using our 60%+ as a cut-off, you can see that Zito has pitched under that quite a few times as a Giant. Remember, the difference between the Nibblin’ classification and the Average classification is over one full run in ERA. That’s assuming that Zito has the same “stuff” and is playing in front of the same excellent defense from years past when he accumulated the bulk of these numbers, both of which aren’t true anymore.

Strikeless In San Francisco

The big question is “Why?”. Why is Zito losing the ability to throw strikes? Why is he trending downward?

A couple of my theories.

1. First and foremost, he has an arm injury or a physical condition that’s preventing him from throwing, releasing, or controlling the ball in the same way he used to. Zito has never been a control pitcher but his current BB% of 13%+ is a career worst. The loss of control — in Zito’s case, the worsening — can be a indicator of arm troubles. We saw it with Noah Lowry last year when his BB% rose to the neighborhood of 12%. I can’t say for certain if Zito is injured or not, but the loss of velocity and control are injury indicators.

2. Since Zito became a full-time starter in 2001 he’s thrown a lot of innings and pitches. From ’01 to ’06 Zito threw 210 innings or greater, not including additional post-season work. We shouldn’t penalize Zito for being durable but he may have started to cross the line between durable and injured somewhere along the way. This is more of a sub-point to the first point I listed, but Zito has shouldered a large workload in his early career. At one point does it become too much? That’s the million dollar question.

3. He’s made mechanical changes in his delivery that have affected his ability to throw strikes. I generally consider mechanical changes a response to health problems. Like the saying goes: “If it ain’t broke, why fix it?” but let’s assume that for whatever reason Zito has changed his mechanics in a non-injury related way. The talk of Zito’s first Spring Training was that he was changing his delivery. This sent everyone into a frenzy — would you like your new $126M pitcher changing what made him good? — and Zito eventually scrapped his new look. We do know that he’s experimented with a lower arm-slot this year in an attempt to regain velocity.

All three of my explanations are related to health problems. Whether it be an out-and-out injury, workload issues, or mechanical changes, they all link back to the physical health of Zito. I can’t believe that he just lost his velocity and control over night. That’s a bit of hyperbole because it didn’t just happen over night. What amazes me is that all the concerns that came with Zito somehow slid past the Giants’ scouts, front office, and talent evaluators. How could anyone not see some of the potential red flags with Barry Zito? Hindsight is 20/20 but everyone had some concerns about Zito. Did the Giants bet against the back-end of Zito’s deal? I think so. I’m sure that the Giants knew that Barry Zito had some indicators that they didn’t like, but they hedged their bets that he could be a good pitcher for the front-end of the deal and they could worry about the back-end when it got there. It’s truly amazing that the Giants have made Zito the centerpiece of their new era, at least for the next 5 years.

It’s such a “Giants” thing to do, too. When the franchise started to get some legs, maybe develop a farm system, they chained the biggest sports contractual blunder ever to their ankles and then tried to go swimming.

In conclusion, while being aggressive (read: throwing more strikes) worked for Zito in the past, I think he has serious concerns about pitch quality and health that just by being aggressive alone he won’t be able to overcome. It looks like Zito phsyically can’t be aggresive or throw strikes consistently. Sticking him in front of a terrible defense — remember how we were going to win games by defense? — hasn’t helped Zito at all. If Zito continues trend downard into the sub-levels of less than 60% strikes thrown, things are really going to get ugly. Sometimes I try to think what Barry Zito will look like in 2013 and all I can think about is a smoking carcas.