What Has Happened to Jeff Samardzija?

Sort our leaderboards by second half ERA in descending order in the American League and Jeff Samardzija sits atop the list with the highest mark. And it’s not even close. His 7.43 ERA might have been less of a surprise if it came from another former White Sox starter Hector Noesi, but the guy affectionately known as “Shark” has been bitten by the bad pitching bug. It’s not even like he has pitched well, but has suffered from some poor fortune like teammate Chris Sale (5.00 ERA in 2nd half vs 2.57 SIERA), as his 4.76 SIERA is fifth worst in the second half. Of course, he wasn’t exactly Samardzija like in the first half either, but a 4.02 ERA compiled while pitching in a hitter’s haven of a ball park and with a terrible defensive unit behind him isn’t so bad.

His full season ERA of 5.27 now is second worst among qualified AL starting pitchers and while an inflated BABIP and his worst full year LOB% of his career is partly to blame, his skills have clearly taken a hit. If we check Baseball-Reference for his pitch type rates, we find that he’s actually throwing strikes at the highest rate of his career. Given his problems with control in the past, one might guess that Samardzija was struggling with the issue again if told his ERA now stands above 5.00. But this is obviously not the case.

Moving on to his next strike type rate, we see that his looking strike (L/Str) is down somewhat from his last two years, but only marginally from his career average. This would certainly reduce his strikeout rate, but only slightly. This isn’t the problem.

Last, we note that his swinging strike rate is at its lowest mark since 2010, when he was still a work in progress. The more familiar SwStk% on our own player page indicates the same thing. Samardzija is simply not getting batters to swing and miss like he used to. Let’s try to figure out why. Below is a table comparing his Whiff% (Brooks Baseball) by pitch type from 2014 to 2015.

His two fastballs have generated similar whiff rates each year, while his cutter has induced swings and misses at an almost identical rate. The answer lies in his two off-speed pitches, the slider and splitter. Heading into the season, Samardzija’s best weapon was his splitter, while his slider was solid in its own right.

To see the splitter’s effectiveness drop off so dramatically is a surprise. It doesn’t appear that the movement on the pitch has changed so significantly judging by the PITCHf/x movement numbers. One might speculate that his splitter just isn’t diving like it used to. But that doesn’t appear to be what’s happening here. I do believe I have stumbled upon the answer, though why it has happened I have no idea.

It all starts with this:

Samardzija has been a marginal ground ball pitcher heading into the season, but this year he has posted his lowest career GB%, representing the first time that rate has fallen below the 40% plateau. And what do we know about the splitter? That it is thrown to the bottom of the strike zone and usually dives below it, inducing a batter to swing and miss as the ball tumbles below the bat. So this is a pitch that you want batters to think will be a strike, but it ends up outside the zone.

Now check this out:

That’s a huge jump we see in 2015. He’s throwing too many strikes with the pitch! You don’t hear that explanation as a negative thing very often. For whatever reason, Samardzija’s splitters are ending up in the zone far more frequently than they used to, which makes it easier for batters to make contact and also loft the ball (his FB% on the pitch is at a career high).

I don’t know if having trouble keeping the ball down and getting the splitter to dive outside the zone is a sign of a hidden injury or what. But it seems to me that I have pinpointed the culprit, at least from a results standpoint. What’s causing this to happen is anyone’s guess. But it’s important to identify because we’ll get a better sense of whether he’ll be able to rebound next year and if so, by how much? Does he become a slightly positive mixed league asset or will the strong skills package from 2012 to 2014 be delivered again?