06 February 2015

What Happened to Bud Norris's Strikeouts?

When Bud Norris came to the Orioles at the 2013 trade deadline, many pundits censured the deal, because Norris appeared to no longer possess the stuff that brought him to the show. In a representative post at FanGraphs, Eno Sarris noted:
In 2010, he threw 93.6 mph and struck out 23.1% of the batters he faced. This year, he's down to 92.4 mph and 16.6% respectively.
Although Norris would finish the year with a 19.0% strikeout rate, that still came in far below his previous norms, corresponding with the aforementioned velocity decline:

Season K%* K%+
2009 21.2% 124
2010 23.1% 131
2011 22.1% 125
2012 22.5% 120
2013 18.9% 100
*As a starter

Unsurprisingly, his xFIP- in 2013 (106) was notably worse than from 2009 to 2012 (100). Because of the negative nature of pitcher aging curves, most suspected that he'd never be the same again.

Then came 2014, in which a funny thing happened. The velocity returned...

Year Fourseam Sinker Change Slider
2009 94.2 0.0 86.9 87.7
2010 94.3 93.6 86.2 87.9
2011 93.6 93.3 83.9 87.0
2012 92.6 92.6 85.8 84.9
2013 93.6 93.2 86.2 85.3
2014 94.5 94.4 86.6 87.7

...but the results remained subpar:

Year K% K%+ xFIP-
2014 20.2% 104 105

His lucky ERA notwithstanding, Norris didn't do much in 2014. But why? If his velocity made a comeback, shouldn't the punchouts have come with it?

First, let's check his peripherals. They support the decline fully: While hitters didn't offer at this pitches any less than they used to (his 45.9% Swing% in 2014 didn't diverge much from his 45.5% mark from 2009 to 2013), they didn't miss nearly as often when they did (his 83.5% Contact% departed significantly from the 76.7% figure he theretofore posted). So an absence of whiffs caused this, but what caused that?

Entering the majors in 2009, Norris only had three pitches: a four-seam fastball, a changeup, and a slider. As the above velocity chart shows, all three of those quickly lost velocity, leading him to integrate a fourth pitch: a sinker. In 2010 and 2011, he threw it less than 7% of the time, but by 2012 — when his velocity hit its nadir — it had become a full member of his arsenal:

Unsurprisingly, Norris's sinker doesn't accrue many whiffs — for his career, it has a SwStr% of 4.3%. So its rise (or sink, I suppose) accounts for some of the disappearance in strikeouts. But most of it is due to the latter of the three aforementioned pitches.

Norris's slider has always been good. Like, really good. According to Jeff Zimmerman, an above-average slider has a whiff rate of 14.4%; Norris's has resulted in a swing-and-a-miss 18.5% of the time. Two years ago, however, that took a turn for the worse, and it hasn't recovered yet:

At 30.7%, Norris's usage rate on the pitch had never been lower.

Remember, Norris regained velocity on every pitch — including his slider — in 2014. That means speed didn't create this, which indicates it may be something within Norris's control. But what?

His location of the pitch stayed the same, as did the rate at which batters swung at it. One thing did change, though: his sequencing. Earlier in his career, he relied on the slider to get tough outs; by 2014, that had changed:

Year(s)  Slider% — Batter Ahead   Slider% — Even   Slider% — Pitcher Ahead 
2009-2013 27.3% 36.4% 42.8%
2014 27.5% 29.9% 34.6%

In a hitter's count, Norris relied on the slider as much as ever; when he had the advantage, though (or when he was close to having the advantage), he decided to eschew it. Its replacement came in the form of his new favorite pitch — the sinker:

Year(s) Sinker% — Batter Ahead Sinker% — Even Sinker% — Pitcher Ahead
2009-2013 8.5% 10.6% 8.7%
2014 11.2% 14.4% 14.3%

To put batters away, Norris no longer leans on his slider, as he's deemed his sinker a worthy substitute. Of course, this means fewer whiffs — a batter won't swing and miss as often in a hitter's count, when he has room with which to work, as he would in a pitcher's count, when he's more desperate. Nevertheless, that tantalizingly low ERA from last year (7% better than average, the best level of Norris's career) might convince him that it's a worthwhile tradeoff.

So, there you have it. If Norris ever decides to get strikeouts again, he can probably do so; all he has to do is decide to put batters away with his slider, instead of his sinker. The stuff is there, but if the mind isn't willing, it won't come to fruition.


Philip said...

Based on this post, do you think that it would be preferable to trade Bud over Chen if the opportunity presented itself?
I like Norris a lot, and he was certainly successful last year, but a lot of that has to do with the defense behind him, especially with the reduced K's.

Ryan Romano said...

I'd say Bud, yeah. He has no history of overperformance (unlike Chen), and they probably stand less change of re-signing him after 2015.

Anonymous said...

Suspect this is Chen's last year since Scott Boras is his agent. Norris has indicated he is willing to listen if the O's approach him but I suspect they wont with the number of arms who appear ready for the fourth or fifth starter spot in the minors.

There is app a $4.5 million dollar diff in salary between Norris and Chen so most teams trading would probably want Chen for a rental esp since Norris is more serviceable then really good for the money.

So has Bud decided to protect his arm by not throwing the slider? Not sure. Be interesting to know if the players read any of these reports and go "really?".

Just as an aside, noted that Law over on ESPN projects Hader as a reliever which makes me feel a little better when I read the MLB note comparing him to Chris Sale. That would be a kick in the head.

Kind of makes me sad to think that Hader, Arrieta, Strop and Rodriguez are elsewhere. Cost of being successful.

Berdj Joseph Rassam said...

Norris started 28 games last season, with only 11 quality starts among them - I think that says it all.

Anonymous said...

You know the beauty about baseball is while you can account for a lot in forms of statistics, you still have to go out there and perform each and every day, or in the case of a SP, every 5th day. The thing I really like about Norris is he goes out there and gives everything he has each time starts. For that matter, we can probably say the same for all the O's starting pitchers.