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Let me start by confessing that I am an unabashed Dodgers fan. Like I would drink paint while bathing in a tub of mercury in a room full of radioactive gases rather than see the Giants win. Like I would sit through five full minutes of a soccer game rather than see the Giants win (OK, maybe I'm exaggerating a little about that one). But the point is that I don't like when the Giants do good or smart things. And I didn't like this offseason very much because the Giants made themselves a lot better. Scarily better. Not only did they add a frontline pitcher in Johnny Cueto (no, Internet, two subpar months does not make Cueto anything less than an ace) and a very underrated center fielder in Denard Span, but they also added everyone's favorite bounceback candidate, Jeff Samardzija. The question remains, though — will Samardzija bounce back, and if so, to what degree?
You probably know about Jeff Samardzija. You probably know that he set all kinds of school records playing football at Notre Dame, then declared for the MLB draft, where the Cubs would select him in the fifth round in 2006 and sign him to a big, 5-year Major League contract. You probably know that he spent most of his first four years in the Majors as a reliever before transitioning to starting in 2012. You also probably know that he was quite excellent from 2012-14, posting an 8.82 K/9, 2.62 BB/9, 3.70 ERA, 3.50 FIP, 3.29 xFIP, and 3.35 SIERA in 608 innings over that time. There's a good chance that you know that he was, to put it frankly, quite awful in 2015. He pitched to a 4.96 ERA, and his peripheral stats (4.23 FIP, 4.31 xFIP, 4.18 SIERA) took major steps back as well.
Why was he so much worse last season? Well, the sabermetric theory of pitching says that a good pitcher will do three things — strike batters out, avoid walking batters, and generate ground balls. Unfortunately, Samardzija heavily regressed in two of those three categories, as his K/9 and GB rate fell to career-lows of 6.86 and 39.0 percent, respectively.
How bad was his drop in ground ball rate? Samardzija was coming off a clip north of 50 percent in 2014, so that 11.2 percentage point drop in ground ball rate was the second-highest drop in recorded history. Granted, batted ball data has only been around since 2002, but that is still 14 years worth of pitching seasons. For those that are curious, number one was Kenny Rogers in 2002-03, which means that Samardzija experienced the largest dip in ground ball rate since 2003. Only two others (James Shields, 2012-13; Dan Haren, 2014-15) have even eclipsed -10.0 percentage points. But now that we found the problem, we still must find the solution — will his ground balls return?
Here are the pitchers with the top 10 drops in ground ball rate from 2013 to 2014 (among qualifiers in both seasons), along with their percentage in 2015.
| Pitcher | 2013 GB% | 2014 GB% | 2013-14 GB% Differential | 2015 GB% | 2014-15 GB% Differential | 2013-2015 GB% Differential |
|---|---|---|---|---|---|---|
| Jordan Zimmermann | 47.6% | 40.1% | -7.5% | 42.0% | 1.9% | -5.6% |
| Rick Porcello | 55.3% | 49.0% | -6.3% | 45.7% | -3.3% | -9.6% |
| Chris Sale | 46.6% | 40.7% | -5.9% | 42.6% | 1.9% | -4.0% |
| Stephen Strasburg | 51.5% | 45.9% | -5.6% | 42.2% | -3.7% | -9.3% |
| A.J. Burnett | 56.5% | 50.9% | -5.6% | 53.4% | 2.5% | -3.1% |
| Doug Fister | 54.3% | 48.9% | -5.4% | 44.6% | -4.3% | -9.7% |
| Kyle Kendrick | 49.4% | 44.6% | -4.8% | 38.8% | -5.8% | -10.6% |
| David Price | 44.9% | 41.2% | -3.7% | 40.4% | -0.8% | -4.5% |
| Ervin Santana | 46.2% | 42.7% | -3.5% | 40.9% | -1.8% | -5.3% |
| Julio Teheran | 37.8% | 34.8% | -3.0% | 39.7% | 4.9% | 1.9% |
(Note: These pitchers did not have to qualify in 2015; in fact, Strasburg, Fister, Kendrick, and Santana didn't. However, everyone on this list threw at least 100 innings in 2015, which is far past the stabilization point for ground ball rate.)
Looking at this table, it appears that the results in the following year were mixed. Four of them regained some of their grounders while six declined even further. This doesn't tell us much about Samardzija next season — his ground ball rate could go up or down. We could've guessed that. However, the far right column tells us much more. Out of the ten pitchers, nine of them never returned to their peak from two years before, and six of those remained at least five percentage points below. Only Julio Teheran returned to his 2013 rate, and he had a sub-40 percent clip to start. This data seems to say that, similar to a sharp decline in velocity, once a pitcher exhibits an extreme decline in ground ball rate, they are unlikely to get it back. If Samardzija pitches the same way, he will probably not return to his 2012-14 groundball rate.
With that said, there is another wrinkle to this. Samardzija did do something different in 2015 that led to his drop in grounders.
| Pitch Type | 2014 Usage % | 2015 Usage % | 2015 GB % | 2015 Whiff % |
|---|---|---|---|---|
| 4-seam Fastball | 30.8% | 33.5% | 38.8% | 8.0% |
| 2-seam Fastball | 24.1% | 8.8% | 54.3% | 7.8% |
| Slider | 20.3% | 24.4% | 41.4% | 11.7% |
| Cutter | 13.4% | 20.2% | 27.7% | 10.3% |
| Splitter | 11.2% | 13.1% | 47.7% | 12.6% |
In 2015, Samardzija increased his cutter usage while drastically decreasing the use of his sinker. His cutter generates ground balls on a paltry 27.7 percent of balls in play, while his sinker induces grounders to the tune of 54.3 percent. In other words, Samardzija stopped throwing the offering that generates the most ground balls while increasing the usage of the pitch that generates the fewest. By using more sinkers and cutting back on the cutter, he could return his ground ball rate to a mark a lot closer to his gaudy 2014 rate of 50.2 percent.
On the other hand, his cutter and sinker don't exhibit outlier swinging strike rates, so this still doesn't explain his disappearing strikeout totals. However, his overall whiff rate dropped only 1.3 percent from 2014 to 2015, and his velocity didn't really change, so it's likely that Samardzija just faced some bad luck last season and will experience a natural improvement in strikeouts. If he goes back to the sinker, a rise in grounders could accompany that.
Jeff Samardzija should naturally have a bounceback season in 2016 simply because he's moving leagues and pitching in front of a much better defense. Also, while he has real issues pitching from the stretch and with runners in scoring position, there's almost no way that he repeats a strand rate of just 67.2 percent. And as mentioned earlier, most of his strikeouts should return. Those reasons alone should forecast a nice rebound.
Even if his ground ball rate stays as low as it was in 2015, his new home park in San Francisco should be much more forgiving towards home runs than the Windy City. But a simple change in pitch selection could propel Samardzija back to the lofty heights that he reached in 2012-14, and that would be quite a scary occurrence for the rest of the NL West.
. . .
Austin Yamada is a contributing writer for Beyond The Box Score.